Components of Borrowings (Detail) - USD ($) $ in Thousands		Sep. 30, 2016	Dec. 31, 2015
Securities sold under agreements to repurchase
Securities sold under agreements to repurchase		$ 118,532	$ 138,614
FHLB borrowings
Short-term advances		25,000
Long-term advances		65,000	65,000
Total FHLB borrowings		90,000	65,000
Subordinated debt		15,464	15,464
Other debt		243	292
Total borrowings		$ 224,239	$ 219,370
Retail	[1]	0.07%	0.13%
Subordinated Debt
FHLB borrowings
Weighted average contractual rate	[1]	3.59%	3.23%
Retail
Securities sold under agreements to repurchase
Securities sold under agreements to repurchase		$ 68,532	$ 88,614
Wholesale
Securities sold under agreements to repurchase
Securities sold under agreements to repurchase		$ 50,000	$ 50,000
Wholesale Repurchase Agreements
FHLB borrowings
Weighted average contractual rate	[1]	3.71%	3.71%
Total FHLB Borrowings
FHLB borrowings
Weighted average contractual rate	[1]	3.01%	4.04%
Total FHLB Borrowings | Short-term advances
FHLB borrowings
Advances	[1]	0.36%
Total FHLB Borrowings | Long-term advances
FHLB borrowings
Advances	[1]	4.04%	4.04%

[1] Weighted average contractual rate