Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014 Segment	Mar. 31, 2013
Significant Accounting Policies Disclosure [Abstract]
Number of operating business segment	1
Amount of net loss increased due to out-of-period adjustment		$ 3.6
Out-of-period adjustment		In the first quarter of 2013, the Company recorded an out-of-period correcting adjustment that increased operating expenses and net loss by $3.6 million for the three months ended March 31, 2013. Management concluded that the adjustment was not material to the full year 2013 results or any previously reported financial statements.