Summary of Provision for Income Taxes from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Federal	$ (1,236)	$ (1,236)	$ (2,471)
Current State and Local Tax Expense (Benefit)	357	0	0
Current Income Tax Expense (Benefit)	(879)	(1,236)	(2,471)
Current income tax expense (benefit), total	(879)	(1,236)	(2,471)
Deferred Federal Income Tax Expense (Benefit)	1,236	1,236	2,471
Deferred State and Local Income Tax Expense (Benefit)	(2,660)	2,137	523
Deferred income tax benefit, total	(1,424)	3,373	2,994
Income tax benefit	$ (2,303)	$ 2,137	$ 523