Fair Value Measurements and Marketable Securities - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Recognized realized gains	$ 5,000	$ 0	$ 0
Recognized realized losses	$ 0	$ 0	$ 0
Weighted average maturity for available for sale securities	6 months 12 days
Shares of common stock to be purchased with warrants	8,300,000
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale securities, longest maturity date	2015-05