Recurring Fair Value Measurements - Summary of Quantitative Information with Respect to Valuation Methodology and Significant Unobservable Inputs Used for Company's Warrant Liabilities (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2014
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
U.S Treasury Yield, period	5 years