Segments and Related Information (Foreign Operations) (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended		6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segments and Related Information [Line Items]
Revenue			$ 1,939,006	$ 1,617,804	$ 3,457,346	$ 3,014,638
Property and equipment, net	$ 852,804	$ 747,808	852,804		852,804
Intangible assets and goodwill, net	1,334,400	1,269,700	1,334,400		1,334,400
United States [Member]
Segments and Related Information [Line Items]
Revenue			1,900,000	1,600,000	3,300,000	3,000,000
Property and equipment, net	819,800	707,400	819,800		819,800
Intangible assets and goodwill, net	1,300,000	1,200,000	1,300,000		1,300,000
Foreign Operations [Member]
Segments and Related Information [Line Items]
Revenue			47,900	$ 26,700	126,700	$ 60,500
Property and equipment, net	33,100	40,400	33,100		33,100
Intangible assets and goodwill, net	$ 63,100	$ 61,500	$ 63,100		$ 63,100
Foreign Operations [Member] | Accounts Receivable, Net, Less BIEC [Member] | Geographic Concentration Risk [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	6.00%	5.00%