Subsequent Events - Additional Information (Detail) - USD ($)	Jul. 02, 2015	Jul. 16, 2015	Jun. 30, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Common Stock, shares authorized			75,000,000	75,000,000
Subsequent Event [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Company's securities for shelf registration	$ 150,000,000
Universal shelf registration amount, maximum	$ 40,000,000
Subsequent Event [Member] | 2011 Equity Incentive Plan [Member]
Subsequent Event [Line Items]
Increase in shares of common stock authorized		2,250,000
Subsequent Event [Member] | 2011 Equity Incentive Plan [Member] | Minimum [Member]
Subsequent Event [Line Items]
Common Stock, shares authorized		8,800,000
Subsequent Event [Member] | 2011 Equity Incentive Plan [Member] | Maximum [Member]
Subsequent Event [Line Items]
Common Stock, shares authorized		11,050,000