Fair Value of Financial Instruments (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Narrative) (Details) - Earn-Out Arrangements [Member] - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Additions from new business combinations, ASC 805 contingent consideration	$ 0	$ 0	$ 33,600,000
Payments of ASC 805 contingent consideration	15,800,000	40,500,000	48,400,000
Receivable [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Reduction in receivable, amount		19,100,000
Other Income or Expense [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
(Increase) reduction in ASC 805 contingent consideration liability, (loss) gain included in earnings	(2,700,000)	20,100,000
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
Level 3 [Member] | Fair Value [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
ASC 805 contingent consideration, fair value	45,800,000	58,400,000
Level 3 [Member] | Fair Value [Member] | Other Current Liabilities [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
ASC 805 contingent consideration, fair value	$ 21,800,000	16,700,000
Level 3 [Member] | Fair Value Measurements, Recurring [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Fair value measurements, valuation techniques	is based on management estimates and entity-specific assumptions, which are Level 3 inputs, and is evaluated on an ongoing basis.
Level 3 [Member] | Fair Value Measurements, Recurring [Member] | Fair Value [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Range of potential undiscounted earn-out liabilities, low	$ 21,800,000
Range of potential undiscounted earn-out liabilities, high	$ 52,700,000
Reduction in ASC 805 contingent consideration liability		39,200,000
Level 3 [Member] | Fair Value Measurements, Recurring [Member] | Fair Value [Member] | Reclassification Adjustment [Member]
Fair Value, Financial Instruments Measured on a Recurring Basis [Line Items]
Reduction in ASC 805 contingent consideration liability		$ 19,100,000