Goodwill and Other Intangible Assets (Schedule of Other Intangible Assets) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 135,061	$ 135,061
Accumulated amortization	(81,174)	(72,605)
Net carrying amount	53,887	62,456
Completed Technologies [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	36,731	36,731
Accumulated amortization	(19,599)	(16,520)
Net carrying amount	17,132	20,211
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	88,700	88,700
Accumulated amortization	(55,660)	(50,832)
Net carrying amount	33,040	37,868
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	8,340	8,340
Accumulated amortization	(4,670)	(4,070)
Net carrying amount	3,670	4,270
Trademarks and Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	800	800
Accumulated amortization	(755)	(693)
Net carrying amount	45	107
Acquired License Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	490	490
Accumulated amortization	(490)	(490)
Net carrying amount	$ 0	$ 0