Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 57,396	$ 69,654	$ 64,275
Restricted cash	17,082	32,864
Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows	$ 74,478	$ 102,518	$ 64,275	$ 75,567