Convertible Preferred Stock - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Jun. 24, 2014	Dec. 31, 2014
Class of Stock [Line Items]
Convertible preferred stock converted to common stock, value		$ 56,155
Common Stock [Member]
Class of Stock [Line Items]
Convertible preferred stock converted to common stock, shares	11,517,222
Convertible preferred stock converted to common stock, value	$ 56,200