Derivatives and Hedging Activities - Collateral With Counterparties (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Pledged securities value	$ 54.3	$ 86.7
Interest rate swap, term of contract	18 months
Federal home loan bank, advances	$ 100.0
Federal home loan bank, interest rate	0.48%
Interest rate swaps
Derivative [Line Items]
Notional amount	$ 100.0
Not Designated as Hedging Instrument \| Interest rate swaps
Derivative [Line Items]
Derivative collateral	51.7	85.6
Notional amount	$ 1,700.0	$ 1,700.0

Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets.

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Amount of right to receive securities collateral under master netting arrangements that have not been offset against derivative liabilities.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Nominal or face amount used to calculate payment on derivative.

+ References

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-SubTopic 10
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Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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- Definition

Amount of advances from the Federal Home Loan Bank (FHLB).

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- Definition

Discloses the single interest rate [if] applicable to the advances from the Federal Home Loan Bank, by branch, as of the Balance Sheet date.

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