Segments and Related Information (Foreign Operations) (Narrative) (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segments and Related Information [Line Items]
Revenue			$ 2,016,618	$ 1,977,227	$ 5,473,965	$ 4,991,865
Property and equipment, net	$ 862,923	$ 747,808	862,923		862,923
Intangible assets and goodwill, net	1,325,800	1,269,700	1,325,800		1,325,800
United States [Member]
Segments and Related Information [Line Items]
Revenue			2,000,000	1,900,000	5,300,000	4,900,000
Property and equipment, net	831,100	707,400	831,100		831,100
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			64,100	$ 41,400	191,000	$ 101,900
Property and equipment, net	31,800	40,400	31,800		31,800
Intangible assets and goodwill, net	$ 62,100	$ 61,500	$ 62,100		$ 62,100
Foreign Operations [Member] | Accounts Receivable, Net, Less BIEC [Member] | Geographic Concentration Risk [Member]
Segments and Related Information [Line Items]
Concentration risk, percentage of total	5.00%	5.00%