Marketable Securities - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Government Debt Securities [Member] \| Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable securities contractual maturities	1 year
Corporate Debt Securities [Member] \| Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable securities contractual maturities	1 year
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable investments continuous unrealized loss position	$ 0	$ 0
Asset-backed Securities [Member] \| Minimum [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable securities contractual maturities	2 years
Asset-backed Securities [Member] \| Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Marketable securities contractual maturities	5 years