Accounts Payable and Accrued Liabilities - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Payables And Accruals [Abstract]
Success fee obligation	$ 27,986us-gaap_ContractualObligation

Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments.

No definition available.

Name:	us-gaap_ContractualObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant