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Derivatives and Balance Sheet Offsetting Balance Sheet Offsetting (Details) - USD ($) $ in Thousands | 3 Months Ended |
--- | --- | ---
Mar. 31, 2019 | Mar. 31, 2018 | Dec. 31, 2018
Balance Sheet Offsetting [Line Items] |  |  |
Document Period End Date | Mar. 31, 2019 |  |
Unrealized Gain (Loss) on Interest Rate Cash Flow Hedges, Pretax, Accumulated Other Comprehensive Income (Loss) | $ 6,268 | $ 0 |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | 23,018 |  |
Repurchase agreements, amounts offset in balance sheet | 0 |  | $ 0
Repurchase agreements, net amount presented in statement of financial position | 23,018 |  | 61,094
Securities Sold under Agreements to Repurchase, Collateral, Right to Reclaim Securities | (23,018) |  | (61,094)
Securities sold under agreements to repurchase, amount not offset | 0 |  | 0
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax | 0 | $ 0 |
Interest Rate Contracts [Member] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Derivative Assets, Gross Amounts Offset in the Balance Sheets | 0 |  | 0
Derivative Asset | 8,815 |  | 7,033
Derivative, Collateral, Obligation to Return Securities | 0 |  | 0
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 8,815 |  | 7,033
Derivative Liability, Gross Amounts Offset in Balance Sheets | 0 |  | 0
Derivative Liability | 8,815 |  | 7,033
Derivative, Collateral, Right to Reclaim Securities | (5,573) |  | (3,235)
Derivative Liability, Fair Value, Amount Not Offset Against Collateral | 3,242 |  | 3,798
Interest rate collar [Domain] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Derivative Assets, Gross Amounts Offset in the Balance Sheets | 0 |  |
Derivative Asset | 6,268 |  |
Derivative, Collateral, Obligation to Return Securities | 0 |  |
Derivative Asset, Fair Value, Amount Not Offset Against Collateral | 6,268 |  |
Available-for-sale Securities [Member] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Securities Sold under Agreements to Repurchase, Gross | 23,018 |  | 61,094
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Assets [Member] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Fair value of asset derivative instruments | 8,815 |  | 7,033
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Liabilities [Member] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Fair value of liability derivative instruments | 8,815 |  | 7,033
Designated as Hedging Instrument [Member] | Interest rate collar [Domain] | Other Assets [Member] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Fair value of asset derivative instruments | 6,268 |  | 0
Designated as Hedging Instrument [Member] | Interest rate collar [Domain] | Other Liabilities [Member] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Fair value of liability derivative instruments | 0 |  | $ 0
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member] |  |  |
Balance Sheet Offsetting [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] |  |  |
Balance Sheet Offsetting [Line Items] |  |  |
Secured Borrowings, Gross Including Not Subject to Master Netting Arrangement | $ 23,018 |  |

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