Income Taxes - Schedule of Provision for Income Taxes with Income Tax at Federal Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Expected income tax (provision) benefit based on US statutory tax rate	$ (272,328)	$ (54,623)	$ 221,359
State income taxes, net of federal benefit	(45,920)	(4,682)	18,829
Tax benefit from US tax reform legislation	0	713,655	0
Tax deficiency from stock-based compensation	259	(3,932)	0
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount	(2,932)	(13,813)	(3,471)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	300	400	1,000
Other, net	13,819	(3,225)	(3,942)
(Provision) benefit for income taxes	$ (307,102)	$ 633,380	$ 232,775
Federal statutory income tax rate	21.00%	35.00%
Effective tax rate	23.70%	(405.80%)	36.80%