Income Taxes - Effective Tax Rate Differs from Federal Statutory Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Taxes at the U.S. federal statutory rate	$ 56,935	$ 76,009	$ 118,936
State income taxes, net of federal tax impact	10,221	13,603	10,712
Domestic production activities deduction	0	0	(7,108)
Non-deductible transaction costs	145	234	541
Change in valuation allowance	(3)	0	3,256
Tax Cuts and Jobs Act	0	(740)	21,961
Federal Energy Credits	(6,873)	0	0
Other, net	3,475	1,446	3,969
Total income tax expense	$ 63,900	$ 90,552	$ 152,267
Effective income tax rate (percent)	23.60%	25.00%	44.80%