Prepaid Expenses and Other Assets - Summary of Prepaid Expenses and Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Prepaid Expense and Other Assets [Abstract]
Prepaid expenses	$ 3,190	$ 6,209
Income tax receivable		4,024
Other	722	167
Total prepaid expenses and other assets	$ 3,912	$ 10,400