Derivative Financial Instruments Notional Amounts and Fair Values of Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Derivatives, Fair Value [Line Items]
Foreign Currency Contract, Fair Value, Net	$ 2,824	$ 1,667
Interest Rate Locks with Customers
Derivatives, Fair Value [Line Items]
Derivatives, at Fair Value, Net	636	1,275
Interest Rate Locks with Customers | Positive fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	87,119	87,781
Derivative Assets, at Fair Value	863	1,291
Interest Rate Locks with Customers | Negative fair values
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	18,239	267
Derivative Liabilities, at Fair Value	(227)	(16)
Forward Commitments
Derivatives, Fair Value [Line Items]
Derivatives, at Fair Value, Net	2,111	181
Forward Commitments | Positive fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	70,031	69,045
Derivative Assets, at Fair Value	2,223	205
Forward Commitments | Negative fair values
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	19,964	16,193
Derivative Liabilities, at Fair Value	(112)	(24)
Interest Rate Swaps with Customers
Derivatives, Fair Value [Line Items]
Derivatives, at Fair Value, Net	7,399	32,860
Interest Rate Swaps with Customers | Positive fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	876,744	846,490
Derivative Assets, at Fair Value	24,397	32,915
Interest Rate Swaps with Customers | Negative fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	583,060	8,757
Derivative Liabilities, at Fair Value	(16,998)	(55)
Interest Rate Swaps with Dealer Counterparties
Derivatives, Fair Value [Line Items]
Derivatives, at Fair Value, Net	(7,399)	(32,860)
Interest Rate Swaps with Dealer Counterparties | Positive fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	583,060	8,757
Derivative Assets, at Fair Value	16,998	55
Interest Rate Swaps with Dealer Counterparties | Negative fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	876,744	846,490
Derivative Liabilities, at Fair Value	(24,397)	(32,915)
Foreign Exchange Contracts with Customers
Derivatives, Fair Value [Line Items]
Foreign Currency Contract, Fair Value, Net	283	(70)
Foreign Exchange Contracts with Customers | Positive fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	11,674	4,897
Foreign Currency Contract, Asset, Fair Value	504	114
Foreign Exchange Contracts with Customers | Negative fair values
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	4,659	8,050
Foreign Currency Contracts, Liability, Fair Value	(221)	(184)
Foreign Exchange Contracts with Correspondent Banks
Derivatives, Fair Value [Line Items]
Foreign Currency Contract, Fair Value, Net	(206)	281
Foreign Exchange Contracts with Correspondent Banks | Positive fair values
Derivatives, Fair Value [Line Items]
Derivative Asset, Notional Amount	7,040	9,728
Foreign Currency Contract, Asset, Fair Value	241	428
Foreign Exchange Contracts with Correspondent Banks | Negative fair values
Derivatives, Fair Value [Line Items]
Derivative Liability, Notional Amount	12,869	6,899
Foreign Currency Contracts, Liability, Fair Value	$ (447)	$ (147)