Fair Value Measurements - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers between fair value measurement levels		$ 0		$ 0
Letter of credit executed				$ 3,400,000	$ 25,000
Fair value measurements charges recognized			$ 300,000		$ 82,000
Closing date of IPO				Dec. 31, 2014
Unrealized loss position of securities for more than 12 months		$ 0		$ 0		$ 0
Letter of Credit [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Letter of credit executed	$ 3,400,000