Acquisitions (Schedule of Measurement Period Adjustments, 2013 Acquisitions, Business Acquisitions) (Details) - USD ($) $ in Thousands	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in Accounting Estimate [Line Items]
Current assets	$ 1,531,751	$ 1,569,727	$ 1,482,610	$ 1,349,995	$ 1,307,026
Goodwill	1,082,466	1,000,024	983,133	912,885	902,044	$ 826,600
Current liabilities	980,848	905,196	863,687	823,181	829,225
Long-term deferred tax liabilities, net	$ 203,476	180,449	186,538	154,151	154,763
As Reported [Member]
Change in Accounting Estimate [Line Items]
Current assets		1,573,952	1,489,652	1,357,936	1,306,000
Goodwill		1,000,024	983,133	912,885	899,400
Current liabilities		910,874	868,474	820,389	825,500
Long-term deferred tax liabilities, net		$ 180,449	$ 186,538	$ 154,151	154,900
Measurement Period Adjustments [Member] | 2013 Acquisitions [Member]
Change in Accounting Estimate [Line Items]
Current assets					1,000
Goodwill					2,600
Current liabilities					3,700
Long-term deferred tax liabilities, net					$ (100)