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Derivatives and Balance Sheet Offsetting (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 0
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement	23,018
Secured Borrowings, Gross, Difference, Amount	0
Gain (Loss) on Interest Rate Cash Flow Hedge Ineffectiveness	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	23,018
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	23,018
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
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
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	0
Not Designated as Hedging Instrument [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Derivative, Notional Amount	369,800		$ 366,700
Gain (Loss) on Derivative Instruments, Net, Pretax		$ 6
Not Designated as Hedging Instrument [Member] \| Other Assets [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of asset derivative instruments	8,815		7,033
Not Designated as Hedging Instrument [Member] \| Other Liabilities [Member] \| Interest Rate Contracts [Member]
Derivative [Line Items]
Fair value of liability derivative instruments	8,815		7,033
Designated as Hedging Instrument [Member] \| Interest rate collar [Domain]
Derivative [Line Items]
Derivative, Notional Amount	500,000
Designated as Hedging Instrument [Member] \| Other Assets [Member] \| Interest rate collar [Domain]
Derivative [Line Items]
Fair value of asset derivative instruments	6,268		0
Designated as Hedging Instrument [Member] \| Other Liabilities [Member] \| Interest rate collar [Domain]
Derivative [Line Items]
Fair value of liability derivative instruments	$ 0		$ 0