Income Taxes (Income Tax Expense) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current income tax expense	$ 48,256	$ 840	$ 58,707
Deferred income tax expense (benefit)	7,614	52,923	(14,493)
Income tax expense, as reported	$ 55,870	$ 53,763	$ 44,214
Effective tax rate	11.20%	10.60%	10.80%