Fair Value Measurements (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Business Acquisition, Contingent Consideration [Line Items]
Additions	$ 0	$ 122,200,000
(Gain) loss on fair value remeasurement of contingent consideration	(547,000)	27,202,000	36,065,000
Payments	(12,500,000)	(6,500,000)
Fair Value, Measurements, Recurring
Business Acquisition, Contingent Consideration [Line Items]
Fair value, end of period	$ 280,900,000	$ 293,900,000	$ 151,000,000