Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 years	Dec. 31, 2010 years
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 135,061	$ 135,061
Accumulated Amortization	(89,675)	(72,605)
Net Carrying Amount	45,386	62,456
Completed Technologies [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	36,731	36,731
Accumulated Amortization	(22,913)	(16,520)
Net Carrying Amount	13,818	20,211
Weighted Average Amortization Period (in years)	6	6
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	88,700	88,700
Accumulated Amortization	(60,202)	(50,832)
Net Carrying Amount	28,498	37,868
Weighted Average Amortization Period (in years)	9	9
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	8,340	8,340
Accumulated Amortization	(5,270)	(4,070)
Net Carrying Amount	3,070	4,270
Weighted Average Amortization Period (in years)	4	4
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	800	800
Accumulated Amortization	(800)	(693)
Net Carrying Amount	0	107
Weighted Average Amortization Period (in years)	4	4
Acquired License Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	490	490
Accumulated Amortization	(490)	(490)
Net Carrying Amount	$ 0	$ 0
Weighted Average Amortization Period (in years)	10	10