Goodwill and Other Intangible Assets (Schedule of Gross Carrying Amount and Accumulated Amortization of Identifiable Intangible Assets, Other Than Goodwill) (Details) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Intangible assets, accumulated amortization	$ (107,392)	$ (95,242)
Total other intangible assets, gross carrying amount	407,113	384,830
Customer Lists and Relationships [Member]
Amortized intangible assets, gross carrying amount	126,701	118,844
Intangible assets, accumulated amortization	(35,658)	(29,973)
Acquired Technology [Member]
Amortized intangible assets, gross carrying amount	101,235	94,689
Intangible assets, accumulated amortization	(57,678)	(53,224)
Trade Names [Member]
Amortized intangible assets, gross carrying amount	58,528	55,320
Intangible assets, accumulated amortization	(10,094)	(8,621)
Unamortized intangible assets, gross carrying amount	113,539	108,633
Other Intangible Assets [Member]
Amortized intangible assets, gross carrying amount	7,110	7,344
Intangible assets, accumulated amortization	$ (3,962)	$ (3,424)