Income Taxes - Schedule of Components of Investments in Qualified Affordable Housing Projects (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Tax credits and other tax benefits - decrease in tax expense	$ (954)	$ (354)
Depreciation - increase in tax expense	$ 757	$ 277