Related Party Transactions - Summary of Balances of Transactions with Related Parties (Parenthetical) (Detail) - USD ($)		Jun. 30, 2015	Dec. 31, 2014
Transactions with Third Party [Line Items]
Accounts payable	[1]	$ 5,010,000	$ 5,260,000
Other long-term liabilities	[1]	45,000	45,000
Unvested Stock Options [Member]
Transactions with Third Party [Line Items]
Accounts payable		200,000	200,000
Other long-term liabilities		$ 45,000	$ 45,000

[1] Includes an account payable of $0.2 million and a long-term liability of $45,000 for both June 30, 2015 and December 31, 2014, related to the unvested portion of stock options as a result of the equitable adjustment approved by our Board of Directors on December 18, 2012 that will be payable to executive officers and employees upon vesting of stock options.