Investments - Amortized Cost and Gross Unrealized Gains and Losses on All Securities (Detail) - Short-term Investments [Member] $ in Thousands	Dec. 31, 2015 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 8,900
Gross Unrealized Gains	0
Gross Unrealized Losses	5
Fair Value	8,895
FDIC Guaranteed Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,920
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair Value	1,920
Corporate Notes/Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,980
Gross Unrealized Gains	0
Gross Unrealized Losses	5
Fair Value	$ 6,975