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Borrowings and Other Obligations - Lines of Credit (Details) - Line of credit - USD ($) $ in Millions | Mar. 31, 2025 | Dec. 31, 2024
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FHLB short-term borrowings |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | $ 925.2 | $ 948.1
Federal reserve bank of san francisco | FRBSF short-term borrowings under the BTFP |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | 325.1 | 358.0
Unsecured debt | FRBSF federal funds purchased |  |
Line of Credit Facility [Line Items] |  |
Lines of credit | $ 125.0 | $ 125.0

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