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Assets Purchased under Resale Agreements and Sold under Repurchase Agreements (Resale Agreements) (Details) - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
Offsetting Assets [Line Items] |  |  |
Gross resale agreements | $ 1,330.0 | $ 1,160.0 |
Loans purchased under agreements to resell | $ 1,020.0 | $ 300.0 |
Loans Purchased Under Resale Agreements |  |  |
Offsetting Assets [Line Items] |  |  |
Weighted average yield (as a percent) | 1.53% | 2.27% |
Securities Purchased Under Resale Agreements |  |  |
Offsetting Assets [Line Items] |  |  |
Weighted average yield (as a percent) | 1.53% | 1.94% | 2.66%

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- Definition Weighted average yield on the amount to be repaid by the counterparty to the resale agreement. + References No definition available. + Details
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- Definition Loans Purchased Under Agreements to Resell + References No definition available. + Details
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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. + References No definition available. + Details
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- Definition Amount, before effects of master netting arrangements, of funds outstanding loaned in the form of a security resale agreement between the entity and another party for the purchase and resale of identical or substantially the same securities at a date certain for a specified price. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 + Details
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