Federal Home Loan Bank Advances and Short-Term Borrowings - Federal Home Loan Bank Advance Owed (Detail) - USD ($) $ in Thousands		Mar. 31, 2016	Dec. 31, 2015
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount		$ 400,849	$ 460,898
FHLB Maturity Date May 19, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount			$ 60,000
Interest Rate			0.49%
FHLB Maturity Date November 25, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount	[1]	$ 40,000	$ 40,000
Interest Rate	[1]	0.44%	0.40%
FHLB Maturity Date November 6, 2017
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount		$ 387	$ 426
Interest Rate		0.50%	0.50%
FHLB Maturity Date November 20, 2017
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount	[1]	$ 50,000	$ 50,000
Interest Rate	[1]	0.42%	0.42%
FHLB Maturity Date November 23, 2018
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount	[1]	$ 50,000	$ 50,000
Interest Rate	[1]	0.42%	0.40%
FHLB Maturity Date December 31, 2019
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount	[1]	$ 50,000	$ 50,000
Interest Rate	[1]	0.39%	0.37%
FHLB Maturity Date May 28, 2020
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount	[1]	$ 60,000	$ 60,000
Interest Rate	[1]	0.44%	0.40%
FHLB Maturity Date August, 11, 2020
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount	[1]	$ 150,000	$ 150,000
Interest Rate	[1]	0.44%	0.44%
FHLB Maturity Date February 10, 2026
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Contractual Outstanding Amount		$ 462	$ 472
Interest Rate		0.00%	0.00%
1 Month FRC | FHLB Maturity Date November 25, 2016
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest Rate, Basis Points	[1]	0.02%	0.02%
1 Month FRC | FHLB Maturity Date November 20, 2017
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest Rate, Basis Points	[1]	0.02%	0.02%
1 Month FRC | FHLB Maturity Date November 23, 2018
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest Rate, Basis Points	[1]	0.02%	0.02%
1 Month FRC | FHLB Maturity Date December 31, 2019
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest Rate, Basis Points	[1]	0.02%	0.02%
1 Month FRC | FHLB Maturity Date May 28, 2020
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest Rate, Basis Points	[1]	0.02%	0.02%
1 Month FRC | FHLB Maturity Date August, 11, 2020
Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items]
Interest Rate, Basis Points	[1]	0.02%	0.02%

[1] FRC = FHLB Fixed Rate Credit interest rate.