Identifiable Intangible Assets - (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets and Goodwill [Line Items]
Goodwill	$ 22,495		$ 22,495		$ 22,495
Goodwill, Acquired During Period			0
Finite-Lived Intangible Assets, Gross	79,753		79,753		73,752
Finite-Lived Intangible Assets, Accumulated Amortization	66,255		66,255		64,710
Intangible Assets, Net (Excluding Goodwill)	13,498		13,498		9,042
Amortization of Intangible Assets	515	$ 567	1,545	$ 1,907
Future Amortization Expense, Remainder of Fiscal Year	593		593
Future Amortization Expense, Year One	2,294		2,294
Future Amortization Expense, Year Two	1,906		1,906
Future Amortization Expense, Year Three	1,470		1,470
Future Amortization Expense, Year Four	1,470		1,470
Future Amortization Expense, Year Five	1,267		1,267
Developed Technology Rights [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	65,831		65,831		59,831
Finite-Lived Intangible Assets, Accumulated Amortization	54,623		54,623		53,417
Intangible Assets, Net (Excluding Goodwill)	11,208		11,208		6,414
Customer Relationships [Member]
Finite-Lived Intangible Assets and Goodwill [Line Items]
Finite-Lived Intangible Assets, Gross	9,561		9,561		9,560
Finite-Lived Intangible Assets, Accumulated Amortization	8,082		8,082		7,818
Intangible Assets, Net (Excluding Goodwill)	1,479		1,479		1,742
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	3,550		3,550		3,475
Intangible Assets, Net (Excluding Goodwill)	$ 811		$ 811		$ 886