Summary of Significant Accounting Policies - Schedule of Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 33,521	$ 75,567	$ 181,796
Restricted cash	34,278		476
Total cash, cash equivalents, and restricted cash shown in our consolidated statements of cash flows	$ 67,799	$ 75,567	$ 182,272	$ 106,006