Financial Instruments Measured at Fair Value Financial Instruments Measured at Fair Value Summary of Level 3 Details (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Business Acquisition, Contingent Consideration, at Fair Value	$ (14,850)
Interest Accretion on Contignent Consideration	(181)
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$ (15,031)	$ 0