Fair Value Measurements (Fair Value of Assets and liabilities Measured on a Recurring Basis) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($) acquisition	Dec. 31, 2018 USD ($)
Liabilities:
Number of businesses acquired | acquisition	4
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	$ (29,406)	$ (4,311)
Recurring
Assets:
Total assets	561	236
Liabilities:
Contingent consideration	137,349	179,911
Total liabilities	141,029	185,303
Recurring | Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset	535
Liabilities:
Derivative liability	169	1,354
Recurring | Designated as Hedging Instrument | Interest Rate Swap Contracts
Liabilities:
Derivative liability	374	865
Recurring | Not Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset		236
Recurring | Not Designated as Hedging Instrument | Freestanding Instrument
Assets:
Derivative asset	26
Liabilities:
Derivative liability	3,137	3,173
Recurring | Level 1
Assets:
Total assets	0	0
Liabilities:
Contingent consideration	0	0
Total liabilities	0	0
Recurring | Level 1 | Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset	0
Liabilities:
Derivative liability	0	0
Recurring | Level 1 | Designated as Hedging Instrument | Interest Rate Swap Contracts
Liabilities:
Derivative liability	0	0
Recurring | Level 1 | Designated as Hedging Instrument | Freestanding Instrument
Assets:
Derivative asset	0
Recurring | Level 1 | Not Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset		0
Recurring | Level 1 | Not Designated as Hedging Instrument | Freestanding Instrument
Liabilities:
Derivative liability	0	0
Recurring | Level 2
Assets:
Total assets	561	236
Liabilities:
Contingent consideration	0	0
Total liabilities	3,680	5,392
Recurring | Level 2 | Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset	535
Liabilities:
Derivative liability	169	1,354
Recurring | Level 2 | Designated as Hedging Instrument | Interest Rate Swap Contracts
Liabilities:
Derivative liability	374	865
Recurring | Level 2 | Not Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset		236
Recurring | Level 2 | Not Designated as Hedging Instrument | Freestanding Instrument
Assets:
Derivative asset	26
Liabilities:
Derivative liability	3,137	3,173
Recurring | Level 3
Assets:
Total assets	0	0
Liabilities:
Contingent consideration	137,349	179,911
Total liabilities	137,349	179,911
Recurring | Level 3 | Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset	0
Liabilities:
Derivative liability	0	0
Recurring | Level 3 | Designated as Hedging Instrument | Interest Rate Swap Contracts
Liabilities:
Derivative liability	0	0
Recurring | Level 3 | Designated as Hedging Instrument | Freestanding Instrument
Assets:
Derivative asset	0
Recurring | Level 3 | Not Designated as Hedging Instrument | Foreign Exchange Contract
Assets:
Derivative asset		0
Recurring | Level 3 | Not Designated as Hedging Instrument | Interest Rate Swap Contracts
Liabilities:
Derivative liability		$ 0
Recurring | Level 3 | Not Designated as Hedging Instrument | Freestanding Instrument
Liabilities:
Derivative liability	$ 0