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Short-Term Borrowings and Other Obligations - Lines of Credit (Details) - Line of credit - USD ($) $ in Millions | Jun. 30, 2023 | Dec. 31, 2022
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Federal home loan bank borrowings |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | $ 1,034.0 | $ 711.6
Federal reserve line of credit |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | 58.0 | 58.7
Federal reserve line of credit | Federal Reserve Bank Term Funding Program |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | 279.0 |
Unsecured debt | Federal funds purchased |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | $ 135.0 | $ 150.0

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