Document and Entity Information [Abstract] Document and Entity Information [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Trading Symbol Trading Symbol Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Statement Of Financial Position [Abstract] Statement of Financial Position [Abstract] Assets [Abstract] ASSETS Assets, Current [Abstract] Current assets: Cash and Cash Equivalents, At Carrying Value Cash and cash equivalents Cash and cash equivalents, primarily include money market funds Cash and cash equivalents Cash and cash equivalents, beginning of period Cash and cash equivalents, end of period Accounts Receivable, Net Accounts receivable, net Accounts receivable, net Inventory, Net Total Inventories Total Deferred Tax Assets, Net, Current Deferred tax assets Prepaid Expense and Other Assets, Current Prepaid expenses and other current assets Prepaid expenses and other current assets Assets, Current Total current assets Total current assets Property, Plant and Equipment, Net Property and equipment, net Property and equipment, net Property, Plant and Equipment, Net, Beginning Balance Property, Plant and Equipment, Net, Ending Balance Available-For-Sale Securities, Debt Securities, Noncurrent Investments Available-for-sale securities fair value Deferred Tax Assets, Net, Noncurrent Long term deferred tax assets Other Assets, Noncurrent Other assets Total Assets Total assets Total assets Liabilities and Equity [Abstract] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities, Current [Abstract] Current liabilities: Accounts Payable, Current Accounts payable Accounts Payable, Current, Total Accrued Liabilities, Current Accrued expenses Accrued Liabilities, Current, Total Employee-Related Liabilities, Current Accrued compensation Employee-related Liabilities, Current, Total Accrued Professional Fees, Current Accrued professional Deferred Revenue, Current Deferred revenue Deferred Revenue, Current, Total Total Current Liabilities Total current liabilities Total current liabilities Deferred Revenue, Noncurrent Long-term deferred revenue Deferred Revenue, Noncurrent, Total Commitments and Contingencies Commitments and contingent liabilities Stockholders Equity Attributable To Parent [Abstract] Stockholders' equity: Preferred Stock, Value, Outstanding Preferred stock, $1.00 par value; 1,000,000 shares authorized, none outstanding Common Stock, Value, Outstanding Common stock, $.01 par value; 70,000,000 shares authorized; issued and outstanding 22,627,375 as of March 31, 2014 and 22,574,251 as of December 31, 2013 Additional Paid In Capital, Common Stock Additional paid-in capital Additional Paid in Capital, Common Stock, Beginning Balance Additional Paid in Capital, Common Stock, Ending Balance Accumulated Other Comprehensive Income (Loss), Net Of Tax Accumulated other comprehensive loss Retained Earnings (Accumulated Deficit) Accumulated deficit Accumulated deficit Retained Earnings (Accumulated Deficit), Beginning Balance Retained Earnings (Accumulated Deficit), Ending Balance Stockholders' Equity Attributable To Parent Total stockholders' equity Total stockholders' equity Balance Balance Liabilities and Equity Total liabilities and stockholders' equity Total liabilities and stockholders' equity Preferred Stock, Par Or Stated Value Per Share Preferred stock, par value (in dollars per share) Preferred Stock, Shares Authorized Preferred stock, shares authorized Preferred Stock, Shares Outstanding Preferred stock, shares outstanding Common Stock, Par Or Stated Value Per Share Common stock, par value (in dollars per share) Common Stock, Shares Authorized Common stock, shares authorized Common Stock, Shares, Issued Common stock, shares issued Common Stock, Shares, Issued, Total Common Stock, Shares, Outstanding Common stock, shares outstanding Balance (in shares) Balance (in shares) Statement Of Income and Comprehensive Income [Abstract] Statement of Income and Comprehensive Income [Abstract] Revenue, Net [Abstract] Revenue: License and Services Revenue Software licenses Maintenance Revenue Software maintenance Sales Revenue, Services, Net Services Hardware Sales Hardware sales Represents hardware sales. Royalty Revenue Royalties Total Revenue Revenue Revenue Total revenue Costs and Expenses [Abstract] Costs and expenses: Cost Of Hardware Sales Cost of hardware sales Represents cost of hardware sales. Cost Of Services Cost of services Research and Development Expense Research and development Selling and Marketing Expense Selling and marketing General and Administrative Expense General and administrative Total Costs and Expenses Expenses Total costs and expenses Total cost and expenses Operating Income Loss Before Patent Related Income Operating income before patent related income The net result for the period of deducting operating expenses from operating revenues before patent related income. Income From Patent Arrangement Income from patent arrangement The net result for the period of deducting operating expenses from operating revenues including patent related income. Operating Income Loss After Patent Related Income Operating income after patent related income Operating income after patent related income The net result for the period of deducting operating expenses from operating revenues after patent related income. Operating income after patent related income Investment Income, Interest Interest income Interest income Loss Before Income Taxes Loss before income taxes Income (loss) from continuing operations before taxes Income from continuing operations before income taxes Income from continuing operations before income taxes Income from continuing operations before income taxes Income Tax Expense (Benefit) Income tax expense Provision for income taxes Income taxes Provision for income taxes Provision for (benefit from) income taxes Income (Loss) From Continuing Operations Attributable To Noncontrolling Interest Income (loss) from continuing operations Income (loss) from continuing operations Income (loss) from continuing operations Income from continuing operations Income (Loss) From Discontinued Operations, Net Of Tax, Attributable To Noncontrolling Interest Income from discontinued operations, net of income taxes Loss from discontinued operations, net of income taxes Net Income Net income Net income Net income Net income Net income Earnings Per Share, Basic [Abstract] Basic net income per share: Income (Loss) From Continuing Operations, Per Basic Share Basic net income per share from continuing operations (in dollars per share) Income (Loss) From Discontinued Operations, Net Of Tax, Per Basic Share Basic net loss per share from discontinued operations (in dollars per share) Earnings Per Share, Basic Basic net income per share Basic net income per share (in dollars per share) Earnings Per Share, Diluted [Abstract] Diluted net income per share: Income (Loss) From Continuing Operations, Per Diluted Share Diluted net income per share from continuing operations (in dollars per share) Income (Loss) From Discontinued Operations, Net Of Tax, Per Diluted Share Diluted net loss per share from discontinued operations (in dollars per share) Earnings Per Share, Diluted Net income (loss) per share - diluted (in dollars per share) Diluted net income per share (in dollars per share) Weighted Average Number Of Shares Outstanding, Basic Weighted-average common shares outstanding (in shares) Weighted-average shares - basic (in shares) Weighted Average Number of Shares Outstanding, Basic, Total Weighted Average Number Of Shares Outstanding, Diluted Weighted-average shares - diluted (in shares) Diluted shares outstanding (in shares) Diluted shares outstanding (in shares) Comprehensive Income (Loss), Net Of Tax, Attributable To Parent [Abstract] Comprehensive income: Other Comprehensive Income (Loss), Net Of Tax [Abstract] Other comprehensive income (net of tax): Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) On Securities Arising During Period, Net Of Tax Unrealized gains on available for sale securities Comprehensive Income (Loss), Net Of Tax, Attributable To Parent Comprehensive income Comprehensive income Statement Of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Net Cash Provided by (Used in) Operating Activities [Abstract] Cash flows from operating activities: Adjustments To Reconcile Net Income (Loss) To Cash Provided By (Used In) Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Depreciation, Depletion and Amortization Depreciation and amortization Depreciation and amortization Share-Based Compensation Stock-based compensation Stock-based compensation Accretion (Amortization) Of Discounts and Premiums, Investments Amortization of discount on investments Amortization of premium on investments Deferred Tax Expenses Benefit On Unrealized Losses On Available For Sale Securities Deferred tax provision on other comprehensive income Amount of tax expense (benefit) of unrealized holding gain (loss) on available-for-sale securities. Deferred tax provision on other comprehensive income Increase (Decrease) In Operating Capital [Abstract] Changes in assets and liabilities: Increase (Decrease) In Accounts Receivable Accounts receivable Accounts receivable Increase Decrease In Receivable From Patent Arrangement Receivable from patent arrangement This element represents increase decrease in receivable from patent arrangement. Increase (Decrease) In Inventories Inventories Inventories Inventories Inventories Increase (Decrease) In Prepaid Expense and Other Assets Prepaid expenses and other current assets Prepaid expenses and other current assets Prepaid expenses and other current assets Increase (Decrease) in Deferred Income Taxes Deferred tax assets Increase (Decrease) In Accounts Payable Accounts payable Accounts payable Increase (Decrease) In Accrued Liabilities Accrued expenses, compensation, and professional Increase (Decrease) In Deferred Revenue Deferred revenue Net Cash Provided by (Used in) Operating Activities, Total Net cash provided by (used in) operating activities Net cash provided by operating activities Net Cash Provided by (Used in) Investing Activities [Abstract] Cash flows from investing activities: Payments To Acquire Property, Plant, and Equipment Purchases of property and equipment Purchases of property and equipment Purchases of property and equipment Net Cash Provided by (Used in) Investing Activities, Total Net cash provided by (used in) investing activities Net cash used in investing activities Net Cash Provided by (Used in) Financing Activities [Abstract] Cash flows from financing activities: Proceeds From Issuance Of Common Stock Proceeds from issuance of common stock Excess Tax Benefit from Share-based Compensation, Financing Activities Excess tax benefits from stock-based compensation Excess tax benefits from stock-based compensation Shares Surrendered By Employees To Pay Taxes Related To Unrestricted Stock Shares surrendered by employees to pay taxes related to unrestricted stock Cash outflow due to shares surrendered by employees to pay taxes related to unrestricted stock. Payments made for taxes of employees who surrendered shares related to unrestricted stock Net Cash Provided by (Used in) Financing Activities, Total Net cash provided by (used in) financing activities Net cash provided by financing activities Cash and Cash Equivalents, Period Increase (Decrease) Increase (decrease) in cash and cash equivalents Increase in cash and cash equivalents Supplemental Cash Flow Information [Abstract] Supplemental disclosure: Income Taxes Paid Cash paid for income taxes Basis Of Accounting [Abstract] Basis Of Accounting [Abstract] Basis Of Accounting [Text Block] Basis of Presentation Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Fair Value Disclosures [Text Block] Fair Value Measurements Inventory Disclosure [Abstract] Inventory Disclosure [Text Block] Inventories Earnings Per Share [Abstract] Earnings Per Share [Abstract] Earnings Per Share [Text Block] Computation of Earnings per Share Disclosure Of Compensation Related Costs, Share-Based Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure Of Compensation Related Costs, Share-Based Payments [Text Block] Stock-Based Compensation Segment Reporting [Abstract] Segment Reporting [Abstract] Segment Reporting Disclosure [Text Block] Business Segments Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Abstract] Accounting Changes and Error Corrections [Text Block] Recent Accounting Pronouncements Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Income Tax Disclosure [Text Block] Income Taxes Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Discontinued Operations Fair Value, Assets Measured On Recurring Basis [Table Text Block] Schedule of assets that are measured at fair value on a recurring basis Schedule of Inventory, Current [Table Text Block] Schedule of inventories Schedule Of Earnings Per Share, Basic and Diluted [Table Text Block] Schedule of net income per share Schedule Of Employee Service Share-Based Compensation, Allocation Of Recognized Period Costs [Table Text Block] Schedule of stock-based employee compensation expense included in unaudited consolidated statements of comprehensive income Schedule Of Revenue From External Customers Attributed To Foreign Countries By Geographic Area [Table Text Block] Schedule of revenues generated from geographic regions Schedule Of Restructuring and Related Costs [Table Text Block] Schedule of rollforward of the exit costs liability accounts Schedule of Disposal Groups, Including Discontinued Operations, Income Statement, Balance Sheet and Additional Disclosures [Table Text Block] Schedule of loss from discontinued operations attributable to the DSL service assurance software product line Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Major Types of Debt and Equity Securities [Axis] Investment Type [Axis] Major Types of Debt and Equity Securities [Domain] Investment Type Categorization [Domain] Corporate Debt Securities [Member] Corporate debt securities Money Market Funds [Member] Money market funds (included in cash and cash equivalents) Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value Measurement, Quoted Prices in Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 2 [Member] Fair Value Measurement, Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 3 [Member] Fair Value Measurement, Significant Unobservable Inputs (Level 3) Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring [Member] Fair value on recurring basis Fair Value, Assets and Liabilities Measured On Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Available-for-sale Securities Available-for-sale investments Corporate debt securities, fair value Inventory, Raw Materials, Net of Reserves Raw materials Inventory, Finished Goods, Net of Reserves Finished goods Net Income (Loss) Attributable To Parent [Abstract] Net income (loss): Net income: Income (Loss) From Continuing Operations Attributable To Parent Income from continuing operations Income (loss) from continuing operations Income (Loss) From Discontinued Operations, Net Of Tax, Attributable To Parent Income from discontinued operations Income from discontinued operations, net of tax Loss from discontinued operations Loss from discontinued operations Weighted Average Number Of Shares Outstanding Reconciliation [Abstract] Shares outstanding: Incremental Common Shares Attributable To Share-Based Payment Arrangements Additional dilutive common stock equivalents (in shares) Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Equity Option [Member] Options Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded From Computation Of Earnings Per Share, Amount Anti-dilutive common stock Share purchase (in shares) Schedule Of Employee Service Share-Based Compensation, Allocation Of Recognized Period Costs [Table] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Income Statement Location [Axis] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs, by Report Line [Axis] Income Statement Location [Domain] Employee Service Share-based Compensation, Allocation of Recognized Period Costs, Report Line [Domain] Cost Of Services [Member] Cost of services Primary financial statement caption in which reported facts about cost of services have been included. Research and Development Expense [Member] Research and development Selling and Marketing Expense [Member] Selling and marketing General and Administrative Expense [Member] General and administrative Employee Service Share-Based Compensation, Allocation Of Recognized Period Costs [Line Items] Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items] Allocated Share-Based Compensation Expense Stock-based compensation charge Stock-based compensation expense Schedule Of Share-Based Compensation Arrangements By Share-Based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Unrestricted Stock Grants [Member] Unrestricted Stock Grants Represent Unrestricted Stock Grants. Award Date [Axis] Award Date [Domain] Grant Date April 2013 [Member] 2013 Grant Represents Grant Date April 2013. Grant Date March 2014 [Member] 2014 Grant Represents Grant Date March 2014. Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event Title of Individual [Axis] Relationship to Entity [Domain] Directors Officer And Employees [Member] Directors, officers and employees Executive of the entity that is appointed to the position by the board of directors, officer and employees. Share-Based Compensation Arrangement By Share-Based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Shares Paid for Tax Withholding for Share Based Compensation Number of common stock shares surrendered by employees withholding taxes Adjustments Related to Tax Withholding for Share-based Compensation Common stock value surrendered by employees withholding taxes Schedule of Segment Reporting Information, by Segment [Table] Statement [Table] Geographical [Axis] Geographical [Axis] Segment, Geographical [Domain] Segment, Geographical [Domain] United States United States Rest Of World [Member] Rest of World Segment Reporting Information [Line Items] Statement [Line Items] Effective Income Tax Rate Reconciliation, At Federal Statutory Income Tax Rate Income tax U.S. statutory rate Deferred Tax Assets, Net Deferred tax assets Deferred Tax Assets, Operating Loss Carryforwards, Domestic Total deferred tax assets of federal research and development credit carryforwards Deferred Tax Assets, Operating Loss Carryforwards, State and Local Total deferred tax assets of state research and development credit carryforwards Disposal Group, Including Discontinued Operation, Revenue Revenue Revenue Total revenue Disposal Group, Including Discontinued Operation, Operating Expense Expenses Total costs and expenses Total cost and expenses Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax Loss before income taxes Income from continuing operations before income taxes Loss before income taxes Income from continuing operations before income taxes Income from continuing operations before income taxes Discontinued Operation, Tax Effect of Discontinued Operation Income tax expense Provision for income taxes Income taxes Provision for income taxes Provision for income taxes Income taxes Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Table] Disposal Group Name [Axis] Disposal Groups, Including Discontinued Operations, Name [Domain] Digital Subscriber Line [Member] DSL Service Assurance Segment Represents information of Digital Subscriber Line. Disposal Groups Classification [Axis] Represents information of Digital Subscriber Line. Disposal Groups Classification [Domain] Represents information of Digital Subscriber Line. Discontinued Operations [Member] Discontinued Operations Restructuring Type [Axis] Type of Restructuring [Domain] Employee Severance [Member] Severance and Employee-Related Costs Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Restructuring Reserve [Roll Forward] Restructuring Reserve Liability for exit costs Balance at January 1, 2014 Balance at March 31, 2014 Discontinued Operations Restructuring Charges Amount charged to expense This element represents amount of restructuring charges related to discontinued operations. Payments To Employee And Assets Write Off Payments Payments Represents the amount paid to employees and asset write-offs. Dsl Service [Member] DSL service assurance software product line Represents component of an entity that usually provides financial and operational oversight and administrative support for DSL service member. Plan Name [Axis] Plan Name [Domain] Nonqualified Stock Plan 2001 [Member] 2001 Nonqualified Stock Plan Represents 2001 Nonqualified Stock Plan. Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Issuance of unrestricted stock (in shares) Number of shares granted (in shares) Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation Equity adjustment to additional paid-in capital Cash and Cash Equivalents, Fair Value Disclosure Money market funds (included in cash and cash equivalents) Assets, Fair Value Disclosure Total assets measured at fair value Stock Issued During Period, Shares, New Issues Number of shares issued (in shares)