Income Taxes - Changes in Unrecognized Tax Benefits Excluding Interest and Penalties (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at January 1	$ 794	$ 608	$ 1,361
Additions for tax positions of prior years	0	186	0
Reductions for tax positions of prior years	(616)	0	(588)
Expiration of statutes of limitations	0	0	(165)
Balance at December 31	$ 178	$ 794	$ 608