Stock-Based Compensation - Summary of Stock Option Award Activity under Stock Incentive Plans (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Outstanding, December 31, 2013			490,160
Number of Shares, Granted	227,000	0	614,000	0
Number of Shares, Exercised			(46,000)
Number of Shares, Outstanding, June 30, 2014	1,058,160		1,058,160
Number of Shares, Options exercisable, June 30, 2014	476,451		476,451
Weighted Average Exercise Price, Outstanding, December 31, 2013			$ 1.34
Weighted Average Exercise Price, Granted			$ 12.11
Weighted Average Exercise Price, Exercised			$ 0.64
Weighted Average Exercise Price, Outstanding, June 30, 2014	$ 7.62		$ 7.62
Weighted Average Exercise Price, Options exercisable, June 30, 2014	$ 2.43		$ 2.43