Fair Value Measurements - Assets Measured and Reported at Fair Value on Recurring Basis Using Significant Level 3 Inputs (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 30,960
Proceeds from sale	(32,250)
Unrealized gain	1,290
Balance at end of period	$ 0