Fair Value Measurements - Assumptions in Valuing Warrant Liability (Detail) (Warrants [Member], USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exercise price	$ 3.50	$ 3.50
Volatility	52.70%	56.20%
Equivalent term (years)	3 years 9 months 7 days	4 years
Risk-free interest rate	1.30%	1.30%