Consolidated Income Tax Expense (benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current
Federal	$ 51,489	$ 58,090	$ 19,036
State	10,307	8,627	1,805
Foreign	144	54	118
Current Income Tax Expense (Benefit), Total	61,940	66,771	20,959
Deferred
Federal	3,448	(7,930)	12,913
State	686	288	3,778
Foreign	(90)	(107)	(118)
Deferred Income Tax Expense (Benefit), Total	4,044	(7,749)	16,573
Total consolidated expense	$ 65,984	$ 59,022	$ 37,532