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Portfolio Loans - Schedule of financial instruments owned and pledged as collateral (Details) - USD ($) $ in Thousands | Sep. 30, 2023 | Dec. 31, 2022
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Financial Instruments Owned and Pledged as Collateral [Line Items] |  |
Portfolio loans, net | $ 7,764,450 | $ 7,634,094
Asset Pledged as Collateral |  |
Financial Instruments Owned and Pledged as Collateral [Line Items] |  |
Portfolio loans, net | 5,710,946 | 5,900,166
FHLB |  |
Financial Instruments Owned and Pledged as Collateral [Line Items] |  |
Portfolio loans, net | 4,852,634 | 5,095,448
Federal Reserve Bank |  |
Financial Instruments Owned and Pledged as Collateral [Line Items] |  |
Portfolio loans, net | $ 858,312 | $ 804,718

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