Identifiable Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	$ 65,633		$ 65,633
Finite-Lived Intangible Assets, Accumulated Amortization	58,235		57,819
Finite-Lived Intangible Assets, Net	7,398		7,814
Amortization of Intangible Assets	416	443
Future Amortization Expense, Remainder of Fiscal Year	1,248
Future Amortization Expense, Year One	1,664
Future Amortization Expense, Year Two	1,405
Future Amortization Expense, Year Three	1,033
Future Amortization Expense, Year Four	925
Future Amortization Expense, Year Five	537
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	53,826		53,826
Finite-Lived Intangible Assets, Accumulated Amortization	48,227		47,879
Finite-Lived Intangible Assets, Net	5,599		5,947
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	7,446		7,446
Finite-Lived Intangible Assets, Accumulated Amortization	6,934		6,905
Finite-Lived Intangible Assets, Net	512		541
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,361		4,361
Finite-Lived Intangible Assets, Accumulated Amortization	3,074		3,035
Finite-Lived Intangible Assets, Net	$ 1,287		$ 1,326