Prepaid Expenses and Other Current Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Prepaid Expense And Other Assets Current [Abstract]
Prepaid insurance	$ 592	$ 294
Sales tax receivable	5,133	5,652
Income tax receivable	902	1,374
Other receivables	181	158
Assets held for sale		2,050
Other	4,228	3,679
Prepaid expenses and other current assets	$ 11,036	$ 13,207