Income Taxes (Components of Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current tax provision:
Federal	$ 24,221	$ 21,498	$ (22,176)
State	65,821	45,228	(10,234)
Foreign	277,846	223,328	133,146
Total current	367,888	290,054	100,736
Deferred tax provision:
Federal	(57,765)	(28,003)	(37,396)
State	164,685	(54,507)	(52,391)
Foreign	(36,854)	(12,229)	4,267
Total deferred	70,066	(94,739)	(85,520)
Provision for income taxes	$ 437,954	$ 195,315	$ 15,216