Income Taxes - Income Tax Reconciliation from Continuing Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income (loss) from continuing operations before income taxes	$ 178,867	$ 31,654	$ 117,254	$ 197,885	$ 113,032	$ (38,774)	$ (39,728)	$ (152,826)	$ 525,660	$ (118,296)	$ 434,242
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent									21.00%	35.00%	35.00%
Federal income taxes									$ 110,389	$ (41,404)	$ 151,985
State and local income taxes, net of federal tax benefit									23,218	(4,606)	17,474
Domestic production activities deduction									0	(5,539)	(6,807)
Non-deductible reorganization and transaction costs									(2,959)	7,598	497
Impact of federal and state rate changes									(23,291)	(262,851)	0
Income tax settlements and other adjustments, net									(909)	634	179,558
Other, net									6,682	4,795	4,495
Income tax (benefit) expense from continuing operations	$ 46,034	$ (22,422)	$ 32,816	$ 56,702	$ (219,767)	$ (20,087)	$ (9,905)	$ (51,614)	$ 113,130	$ (301,373)	$ 347,202
Effective tax rate									21.50%	254.80%	80.00%