Stock-Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended		0 Months Ended							6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Mar. 31, 2014 Vested options held by 1 employees	Jun. 14, 2013 Vested options held by 1 employees	May 31, 2013 Vested options held by 1 employees	Jun. 14, 2013 Vested options held by 1 employees Before Extension	May 31, 2013 Vested options held by 1 employees Before Extension	Jun. 14, 2013 Vested options held by 1 employees After Extension	May 31, 2013 Vested options held by 1 employees After Extension	Jun. 30, 2014 Employee Stock Option	Jun. 30, 2014 Unvested Restricted Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, granted	23,800	1,315,500	104,300	1,426,400
Weighted-average grant date fair value	$ 2.84	$ 1.77	$ 3.23	$ 1.89
Unrecognized compensation costs	$ 6.2		$ 6.2
Expected recognition period												1 year 7 months 2 days	1 year 1 month 2 days
Shares vested					71,167	71,167	66,667
Shares vesting period					9 months			3 months	3 months	12 months	12 months
Unrecognized compensation costs related to unvested restricted stock outstanding													$ 0.7