Fair Value of Financial Instruments - Carrying Amounts and Estimated Fair Values of Financial Assets and Liabilities (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Commercial hedge loan adjustment to market change	$ 146	$ 165