Derivatives - (Narrative) (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) item	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($) item
Derivative [Line Items]
Number of interest rate lock commitments | item			78
Number of forward loan sale commitments | item			70
Number of forward contracts | item			11
Notional amount | $	$ 11,300		$ 11,800
Gain (loss) related to hedge ineffectiveness | $	(177)	$ (662)
Termination value of derivatives in net liability position | $	600		1,300
Collateral Already Posted, Aggregate Fair Value | $	$ 900		800
Number OF Interest Rate Loack Commitments Member
Derivative [Line Items]
Number of interest rate lock commitments | item	91
Interest Rate Lock Commitments Notional Amount Member
Derivative [Line Items]
Notional amount | $			13,800
Forward Loan Sales Commitments Notional Amount Member
Derivative [Line Items]
Notional amount | $	$ 1,300		$ 12,000
Designated as Hedging Instrument [Member] | Interest rate swap derivatives [Member]
Derivative [Line Items]
Number of interest rate swaps held | item	49		42
Notional amount | $	$ 340,100		$ 313,000
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Number of forward loan sale commitments | item	11
Number of forward contracts | item	10
Not Designated as Hedging Instrument [Member] | Interest rate swap derivatives [Member]
Derivative [Line Items]
Number of interest rate swaps held | item	38		36
Notional amount | $	$ 143,700		$ 132,600