Segments and Related Information (Foreign Operations) (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2018	Mar. 31, 2017
Segments and Related Information [Line Items]
Revenue			$ 1,396,834	$ 1,158,184
Property and equipment, net	$ 709,806	$ 706,506	709,806
Intangible assets and goodwill, net	1,332,900	1,328,900	1,332,900
United States [Member]
Segments and Related Information [Line Items]
Revenue			1,400,000	1,100,000
Property and equipment, net	658,100	649,500	658,100
Intangible assets and goodwill, net	1,200,000	1,200,000	1,200,000
Foreign Operations [Member]
Segments and Related Information [Line Items]
Revenue			33,800	$ 59,200
Property and equipment, net	51,700	57,000	51,700
Intangible assets and goodwill, net	$ 109,500	$ 112,800	$ 109,500
Foreign Operations [Member] | Accounts Receivable, Net, Less BIEC [Member] | Geographic Concentration Risk [Member] | Foreign Customers [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	5.00%	5.00%