Income Taxes - Summary of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$ 117	$ 65	$ 39
Increases in positions taken in a current period	38	52	65
Decreases due to settlements	(15)	0	(39)
Decreases due to lapse of statute of limitations	0	0	0
Balance at end of period	$ 140	$ 117	$ 65