Goodwill and Other Intangible Assets (Details 2) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Components of amortized intangible assets
Gross Carrying Amount	$ 341,858,000	$ 339,355,000
Accumulated Amortization	(122,485,000)	(116,880,000)
Amortization expense for intangible assets	4,600,000	4,500,000
Estimated amortization expense
Remainder of 2012	13,400,000
2013	17,400,000
2014	16,300,000
2015	16,000,000
2016	16,000,000
2017	16,000,000
Contract based
Components of amortized intangible assets
Gross Carrying Amount	20,949,000	20,793,000
Accumulated Amortization	(13,496,000)	(13,571,000)
Technology based
Components of amortized intangible assets
Gross Carrying Amount	91,788,000	91,269,000
Accumulated Amortization	(36,889,000)	(35,287,000)
Marketing related
Components of amortized intangible assets
Gross Carrying Amount	26,643,000	26,304,000
Accumulated Amortization	(14,308,000)	(13,868,000)
Customer based
Components of amortized intangible assets
Gross Carrying Amount	202,478,000	200,989,000
Accumulated Amortization	$ (57,792,000)	$ (54,154,000)