Schedule of Assumptions (Detail) (USD $)	6 Months Ended		12 Months Ended
	Jun. 30, 2014		Dec. 31, 2013
Class of Warrant or Right [Line Items]
Expected dividend yield	0.00%	[1]	0.00%	[1]
Shares underlying warrants classified as liabilities	501,494		791,508
Market value of stock at beginning of the period	$ 20.37		$ 25.80
Market value of stock at end of the period	$ 29.79		$ 20.37
Minimum [Member]
Class of Warrant or Right [Line Items]
Risk-free interest rate	0.10%	[2]
Expected lives	1 month 6 days	[3]	7 months 6 days	[3]
Expected volatility	48.20%	[4]
Maximum [Member]
Class of Warrant or Right [Line Items]
Risk-free interest rate			0.10%	[2]
Expected lives	2 months 12 days	[3]	8 months 12 days	[3]
Expected volatility	62.10%	[4]	95.50%	[4]

[1] The expected dividend yield is zero as the Company has not paid any dividends to date and does not expect to pay dividends prior to the expiration of the warrants.

[2] The risk-free interest rate is estimated using an average of U.S. Treasury bill interest rates that correlate to the prevailing interest rates at the valuation date.

[3] The expected lives are based on the remaining contractual lives of the related warrants at the valuation date.

[4] The expected volatility is estimated using implied volatility in exchange-traded options associated with the Company's common stock.