Fair Value of Financial Instruments (Fair Value of Financial Instruments, Recurring Basis Measurements) (Narrative) (Details) - Earn-Out Arrangements [Member] - USD ($)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Additions from new business combinations, ASC 805 contingent consideration	$ 0	$ 8,700,000
Payments of ASC 805 contingent consideration	0	0
Foreign Currency Translation Adjustments [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Foreign currency translation gains, other comprehensive income, ASC 805 contingent consideration	4,600,000	$ 1,400,000
Level 3 [Member] | Fair Value [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
ASC 805 contingent consideration, fair value	$ 141,500,000		$ 146,100,000
Level 3 [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Fair value measurements, valuation techniques	The fair value of ASC 805 contingent consideration is based on management estimates and entity-specific assumptions, which are Level 3 inputs, and is evaluated on an ongoing basis.