Summary of Accounts Payable and Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Accounts Payable and Accrued Liabilities [Line Items]
Research and development expenses	$ 4,354	$ 3,024
Consulting and other professional fees	5,319	3,192
Compensation and employee benefits	4,026	4,291
Royalties payable	3,573	4,555
Other	1,854	1,134
Accounts payable and accrued liabilities	$ 19,126	$ 16,196