Provision for Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2018	[1]	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	[1]	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Current:
Federal											$ (507)		$ (3,690)		$ 4,981
State and local											(167)		532		567
Current Income Tax Expense (Benefit), Total											(674)		(3,158)		5,548
Deferred
Federal											(693)		4,293		949
State and local											(337)		(288)		131
Deferred Income Tax Expense (Benefit)											(1,030)		4,005		1,080
Expense for income taxes	$ 71		$ 9,447	$ (10,158)	$ (1,064)	$ (7,389)		$ (652)	$ 5,314	$ 3,574	$ (1,704)	[2]	$ 847	[2]	$ 6,628

[1] As discussed previously, the fourth quarter 2017 results include the results of ARI subsequent to the acquisition on October 10, 2017.

[2] The sum of the net earnings per share may not add up to the full year amount due to rounding and because the quarterly calculations are based on varying numbers of shares outstanding.