Goodwill and Purchased Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 22,553	$ 15,361	$ 4,492
Business Combination, Goodwill Recognized, Description	6989	10756
Business Combination Goodwill Recognized Description2	203	113
Finite-Lived Intangible Assets, Gross	73,752	72,034
Finite-Lived Intangible Assets, Accumulated Amortization	62,288	59,676
Intangible Assets, Net (Excluding Goodwill)	11,464	12,358
Amortization of Intangible Assets	2,592	1,853	1,757
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	2,422
Finite-Lived Intangible Assets, Amortization Expense, Year Two	2,050
Finite-Lived Intangible Assets, Amortization Expense, Year Three	1,941
Finite-Lived Intangible Assets, Amortization Expense, Year Four	1,553
Finite-Lived Intangible Assets, Amortization Expense, Year Five	1,117
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	59,831	58,961
Finite-Lived Intangible Assets, Accumulated Amortization	51,496	49,358
Intangible Assets, Net (Excluding Goodwill)	8,335	9,603
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	9,560	8,712
Finite-Lived Intangible Assets, Accumulated Amortization	7,449	7,102
Intangible Assets, Net (Excluding Goodwill)	2,111	1,610
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	4,361	4,361
Finite-Lived Intangible Assets, Accumulated Amortization	3,343	3,216
Intangible Assets, Net (Excluding Goodwill)	$ 1,018	$ 1,145