Commitments and Contingencies (Commercial Loan Swaps) (Detail) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Interest Rate Swap [Member]
Derivative [Line Items]
Notional Amount		$ 43,000	$ 43,000
Derivative, Fair Value, Net	[1]	(8,372)	(9,229)
ERROR in label resolution.
Derivative [Line Items]
Notional Amount		50,000	50,000
Derivative, Fair Value, Net	[2]	$ (389)	$ (576)
federal home loan bank 30-day [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held		50	28
Notional Amount		$ 266,263	$ 142,944
Derivative, Fair Value, Net		$ (1,945)	$ 3,166
Commercial and Industrial Sector [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held		50	28
Notional Amount		$ 266,263	$ 142,944
Derivative, Fair Value, Net		$ 1,945	$ (3,166)
Loans [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, Number of Instruments Held		100	56
Notional Amount		$ 532,526	$ 285,888
Derivative, Fair Value, Net		$ 0	$ 0

[1] Presented within accrued interest and other liabilities on the consolidated statements of condition.

[2] (1) Presented within accrued interest and other liabilities on the consolidated statements of condition.