Accounts Payable and Accrued Liabilities - Schedule of Components of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Front-end engineering and design	$ 776	$ 12,549
Payroll and compensation	10,507	6,311
Professional services (e.g., legal, audit)	2,736	2,323
Other	4,851	3,220
Total accounts payable and accrued liabilities	$ 18,870	$ 24,403