Derivative Instruments and Hedging Activities - Value of Derivative Assets and Derivative Liabilities (Details) - Not Designated as Hedging Instruments - USD ($) $ in Thousands		Jun. 30, 2017	Dec. 31, 2016
Other Assets
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)		$ 5,442	$ 6,960
Collateral posted, Derivatives	[1]	0	0
Other Assets | Interest rate swap contracts - commercial loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)		5,442	6,960
Notional amount, Derivatives (included in Other Assets)		228,298	232,396
Collateral posted, Derivatives		0	0
Other Assets | Interest rate lock commitments - mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)		456	236
Notional amount, Derivatives (included in Other Assets)		14,585	8,490
Other Assets | Forward sale contracts - mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Assets)		14	0
Notional amount, Derivatives (included in Other Assets)		13,911	0
Other Liabilities
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)		5,423	6,958
Collateral posted, Derivatives	[1]	3,939	14,340
Other Liabilities | Interest rate swap contracts - commercial loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)		5,423	6,958
Notional amount, Derivatives (included in Other Liabilities)		228,298	232,396
Collateral posted, Derivatives		0	14,340
Other Liabilities | Interest rate lock commitments - mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)		0	0
Notional amount, Derivatives (included in Other Liabilities)		0	0
Other Liabilities | Forward sale contracts - mortgage loans
Derivatives not Designated as Hedging Instruments
Fair value, Derivatives (included in Other Liabilities)		0	27
Notional amount, Derivatives (included in Other Liabilities)		$ 0	$ 8,216

[1] Amounts represent posted collateral.