Discontinued Operations - Assets and Liabilities of Discontinued Operations on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Disposal Group Including Discontinued Operation Balance Sheet Disclosures [Abstract]
Deferred income tax assets, net	$ 178	$ 178
Total assets of discontinued operations	178	178
Accounts payable and accrued expenses	3	51
Remaining lease obligations		485
Total current liabilities	3	536
Total liabilities of discontinued operations	$ 3	$ 536