Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

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Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

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Derivatives and Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 6	$ 9	$ 12	$ 2
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	40,933		40,933
Secured Borrowings, Gross, Difference, Amount	0		0
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	40,933		40,933
Maturity Overnight [Member] \| U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	15,933		15,933
Maturity Less than 30 Days [Member] \| U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0		0
Maturity 30 to 90 Days [Member] \| U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	0		0
Maturity Greater than 90 Days [Member] \| U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Derivative [Line Items]
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	25,000		25,000
Not Designated as Hedging Instrument [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	380,000		380,000		$ 309,300
Not Designated as Hedging Instrument [Member] \| Other Assets [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of asset derivative instruments	8,992		8,992		9,012
Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of liability derivative instruments	$ 9,004		$ 9,004		$ 9,036