Investments - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Investment [Line Items]
Maximum maturity days for cash equivalents	90 days
Corporate Bonds, Commercial Paper, Government Securities and Treasury Bonds [Member]
Investment [Line Items]
Remaining maturity period of investments	12 months	12 months