Identifiable Intangible Assets - (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	$ 65,633		$ 65,633		$ 65,633
Finite-Lived Intangible Assets, Accumulated Amortization	58,651		58,651		57,819
Identifiable intangible assets, net	6,982		6,982		7,814
Amortization of Intangible Assets	416	444	832	887
Future Amortization Expense, Remainder of Fiscal Year	833		833
Future Amortization Expense, Year One	1,664		1,664
Future Amortization Expense, Year Two	1,405		1,405
Future Amortization Expense, Year Three	1,033		1,033
Future Amortization Expense, Year Four	925		925
Future Amortization Expense, Year Five	537		537
Goodwill	11,269		11,269		4,492
Business Acquisition, Purchase Price Allocation, Goodwill Amount	6,777		6,777
Developed Technology Rights [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	53,826		53,826		53,826
Finite-Lived Intangible Assets, Accumulated Amortization	48,549		48,549		47,879
Identifiable intangible assets, net	5,277		5,277		5,947
Customer Relationships [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	7,446		7,446		7,446
Finite-Lived Intangible Assets, Accumulated Amortization	6,963		6,963		6,905
Identifiable intangible assets, net	483		483		541
Trade Names [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	4,361		4,361		4,361
Finite-Lived Intangible Assets, Accumulated Amortization	3,139		3,139		3,035
Identifiable intangible assets, net	$ 1,222		$ 1,222		$ 1,326