Fair Value Measurements - Schedule of Reconciliation of Debt Securities (Detail) - Debt Securities [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 12,658
Accrued interest income	316
Unrealized loss on debt securities	(824)	$ (3,300)
Ending balance	$ 12,150	$ 12,658