Fair Value of Financial Instruments (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Business combinations, contingent consideration liability, decrease	$ 20,073,000	$ 0	$ 0
Earn-Out Arrangements [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Additions from new business combinations, ASC 805 contingent consideration	0	33,600,000	32,500,000
Payments of ASC 805 contingent consideration	40,500,000	48,400,000	8,500,000
Earn-Out Arrangements [Member] | 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	8,000,000	4,500,000	$ 2,200,000
Earn-Out Arrangements [Member] | Receivable [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Reductions in other assets, amount	19,100,000
Earn-Out Arrangements [Member] | Other Income, Net [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Business combinations, contingent consideration, gain included in earnings	20,100,000
Earn-Out Arrangements [Member] | Fair Value [Member] | Level 3 [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
ASC 805 contingent consideration, fair value	$ 58,400,000	$ 146,100,000
Fair Value Measurements, Recurring [Member] | Earn-Out Arrangements [Member] | Level 3 [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.
Fair Value Measurements, Recurring [Member] | Earn-Out Arrangements [Member] | Fair Value [Member] | Level 3 [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Business combinations, contingent consideration liability, decrease	$ 39,200,000
Fair Value Measurements, Recurring [Member] | Earn-Out Arrangements [Member] | Fair Value [Member] | Level 3 [Member] | Reclassification Adjustment [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Business combinations, contingent consideration liability, decrease	$ 19,100,000