Identifiable Intangible Assets - (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets and Goodwill [Line Items]
Goodwill	$ 22,495		$ 22,495
Goodwill, Acquired During Period	0
Business Acquisition Purchase Price Allocation Goodwill Amount 2	0
Finite-Lived Intangible Assets, Gross	73,752		73,752
Finite-Lived Intangible Assets, Accumulated Amortization	65,225		64,710
Intangible Assets, Net (Excluding Goodwill)	8,527		9,042
Amortization of Intangible Assets	515	670
Future Amortization Expense, Remainder of Fiscal Year	1,535
Future Amortization Expense, Year One	1,941
Future Amortization Expense, Year Two	1,553
Future Amortization Expense, Year Three	1,117
Future Amortization Expense, Year Four	1,117
Future Amortization Expense, Year Five	914
Developed Technology Rights [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	59,831		59,831
Finite-Lived Intangible Assets, Accumulated Amortization	53,819		53,417
Intangible Assets, Net (Excluding Goodwill)	6,012		6,414
Customer Relationships [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	9,560		9,560
Finite-Lived Intangible Assets, Accumulated Amortization	7,906		7,818
Intangible Assets, Net (Excluding Goodwill)	1,654		1,742
Trade Names [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	4,361		4,361
Finite-Lived Intangible Assets, Accumulated Amortization	3,500		3,475
Intangible Assets, Net (Excluding Goodwill)	$ 861		$ 886