Income Taxes - Schedule of Provision for Income Tax Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current expense (benefit)	$ 114,221	$ (115,195)	$ 84,827
Deferred expense	30,703	153,518	71,257
Tax credits	(4,363)	(5,179)	(5,618)
Tax benefits attributable to items charged to equity and goodwill	(25,123)	(866)	0
Total income tax expense	115,438	32,278	150,466
Other items, net tax benefit	(7,301)	$ (60,196)	46,436
Other items, unrecognized state tax credit	3,500
Other items, TCJA remeasurement	2,300		51,000
Other Items, equity based compensation	$ 900		$ 3,000