Income Taxes - Income Tax Expense (Benefit) Included in Consolidated Statements of Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal									$ 18,816	$ 18,079	$ 15,749
Foreign									42	43	47
State and local									2,681	2,694	1,782
Total									21,539	20,816	17,578
Deferred:
Federal									4,148	1,060	952
State and local									712	953	1,624
Total									4,860	2,013	2,576
Provision for income taxes from continuing operations	$ (967)	$ 7,260	$ 5,306	$ 14,800	$ (2,226)	$ 6,787	$ 4,696	$ 13,572	26,399	22,829	20,154
Operations of discontinued operations:
Current									(365)	(1,263)	51
Deferred									(10)	68	(222)
Total									(375)	(1,195)	(171)
Gain on disposal of discontinued operations:
Current										427	34
Deferred										(344)
Total										83	34
Total income tax expense from discontinued operations									(375)	(1,112)	(137)
Total income tax expense									$ 26,024	$ 21,717	$ 20,017