Loss Contingency - Narrative (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loss Contingencies [Line Items]
Loans held-for-sale involved in fraud		$ 5,200
Range of possible loss, minimum		1,500
Range of possible loss, maximum		3,200
Loss contingency		$ 2,000	$ 0	$ 0	$ 2,000
Loan held for sale not involved in fraud	$ 1,000
Loans recovered in cash from alleged perpetrator	1,500
Loans transferred to other assets	2,700
Reserve transferred to other assets	$ 2,000
Fraud on Loans Held for Sale | Other assets
Loss Contingencies [Line Items]
Net amount of receivable and reserve remaining in other assets			$ 600