Summary of Provision for Income Taxes from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal	$ (1,236)	$ (2,471)	$ 0
Current income tax expense (benefit), total	(1,236)	(2,471)	0
Federal	1,236	2,471	(4,943)
State	2,137	523	0
Deferred income tax benefit, total	3,373	2,994	(4,943)
Income tax benefit	$ 2,137	$ 523	$ (4,943)