Income Taxes - Components of Consolidated Income Tax Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current:
Federal	$ 20,658	$ 16,407	$ 22,477
State	1,297	1,004	732
Total Current	21,955	17,411	23,209
Deferred:
Federal	732	(1,389)	12,965
State	140	(73)	(165)
Total Deferred	872	(1,462)	12,800
Income tax expense, Total	$ 22,827	$ 15,949	$ 36,009