Acquisitions (Schedule of Measurement Period Adjustments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Change in Accounting Estimate [Line Items]
Current assets	$ 1,305,983	$ 1,049,641
Property and equipment, net	488,132	348,858
Goodwill	899,364	826,629	714,800
Other long-term assets, including discontinued operations	60,553	54,160
Current liabilities	825,546	714,135
Scenario, Previously Reported [Member]
Change in Accounting Estimate [Line Items]
Current assets		1,047,100
Property and equipment, net		350,400
Goodwill		820,300
Other long-term assets, including discontinued operations		53,100
Current liabilities		705,700
Scenario, Adjustment [Member] | Purchase Price Allocation Adjustments [Member] | 2012 Acquisitions [Member]
Change in Accounting Estimate [Line Items]
Current assets		2,500
Property and equipment, net		(1,500)
Goodwill		6,300
Other long-term assets, including discontinued operations		1,100
Current liabilities		$ 8,400