Fair Value Measurements - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2016 Security
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments in gross unrealized loss position	5
Available-for-sale investments in gross unrealized loss position	12 months
Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale investments effective maturity period	15 months