Investments - Amortized Cost and Gross Unrealized Gains and Losses on All Securities (Detail) - Short-term Investments [Member] - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 1,007	$ 8,900
Gross Unrealized Gains	0	0
Gross Unrealized Losses		5
Fair Value	1,007	8,895
FDIC Guaranteed Certificates of Deposit [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,920
Gross Unrealized Gains		0
Fair Value		1,920
Corporate Notes/Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	1,007	6,980
Gross Unrealized Gains	0	0
Gross Unrealized Losses		5
Fair Value	$ 1,007	$ 6,975