Income Taxes Income Taxes Details 3 (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Taxes [Abstract]
Computed tax provision at the applicable federal statutory income tax rate									$ 97,531	$ 92,764	$ 140,090
State and local taxes, net of federal income tax benefits									20,081	10,146	8,216
Foreign jurisdiction differences									1,646	2,377	(6,782)
Permanent differences associated with dispositions									1,288	790	1,925
Changes in uncertain tax positions									(9,842)	(88,687)	(105,821)
Foreign Valuation Allowance, Amount									43	(431)	1,186
Enactment of US Tax Reform									0	(16,105)	(146,160)
Excess tax benefit from share-based compensation									(13,868)	(11,159)	(18,521)
Other									(2,218)	4,479	(20,722)
Provision for income taxes	$ (47,999)	$ (1,997)	$ (23,570)	$ (21,095)	$ 67,224	$ (17,043)	$ (16,034)	$ (28,321)	$ 94,661	$ (5,826)	$ (146,589)
Total effective tax rate									20.40%	(1.30%)	(36.60%)