Other Real Estate Owned - Summary of Other Real Estate Owned Activity (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Activity in Other Real Estate Owned
Balance at beginning of period		$ 35,491	$ 63,460
Additions		4,389	10,381
Capitalized improvements		159	251
OREO valuation adjustments, net	$ (4,937)	(1,493)	(7,840)
Sales		(18,175)	(30,761)
Balance at end of period	$ 63,460	$ 20,371	$ 35,491