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Investment Securities - Mortgage-backed Asset Securities (Details) - USD ($) $ in Millions | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Total mortgage-backed securities |  |
Investment securities |  |
Fair value investments | $ 231.9 | $ 256.5
Total mortgage-backed securities | Level 2 |  |
Investment securities |  |
Fair value investments | 231.9 | 256.5
Total mortgage-backed securities | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | FNMA |  |
Investment securities |  |
Fair value investments | 124.5 | 125.4
Total mortgage-backed securities | FNMA | Level 2 |  |
Investment securities |  |
Fair value investments | 124.5 | 125.4
Total mortgage-backed securities | FNMA | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | FHLMC |  |
Investment securities |  |
Fair value investments | 78.8 | 90.5
Total mortgage-backed securities | FHLMC | Level 2 |  |
Investment securities |  |
Fair value investments | 78.8 | 90.5
Total mortgage-backed securities | FHLMC | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | GNMA |  |
Investment securities |  |
Fair value investments | 28.3 | 40.1
Total mortgage-backed securities | GNMA | Level 2 |  |
Investment securities |  |
Fair value investments | 28.3 | 40.1
Total mortgage-backed securities | GNMA | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | Total agency |  |
Investment securities |  |
Fair value investments | 231.6 | 256.0
Total mortgage-backed securities | Total agency | Level 2 |  |
Investment securities |  |
Fair value investments | 231.6 | 256.0
Total mortgage-backed securities | Total agency | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | Non-agency: Residential |  |
Investment securities |  |
Fair value investments | 0.3 | 0.5
Total mortgage-backed securities | Non-agency: Residential | Level 2 |  |
Investment securities |  |
Fair value investments | 0.3 | 0.5
Total mortgage-backed securities | Non-agency: Residential | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | Total non-agency |  |
Investment securities |  |
Fair value investments | 0.3 | 0.5
Total mortgage-backed securities | Total non-agency | Level 2 |  |
Investment securities |  |
Fair value investments | 0.3 | 0.5
Total mortgage-backed securities | Total non-agency | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total other asset-backed securities |  |
Investment securities |  |
Fair value investments | 22.3 | 21.1
Total other asset-backed securities | Level 2 |  |
Investment securities |  |
Fair value investments | 22.3 | 21.1
Total other asset-backed securities | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total other asset-backed securities | Credit card receivables |  |
Investment securities |  |
Fair value investments | 11.9 | 12.3
Total other asset-backed securities | Credit card receivables | Level 2 |  |
Investment securities |  |
Fair value investments | 11.9 | 12.3
Total other asset-backed securities | Credit card receivables | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total other asset-backed securities | Vehicle receivables |  |
Investment securities |  |
Fair value investments | 10.4 | 8.8
Total other asset-backed securities | Vehicle receivables | Level 2 |  |
Investment securities |  |
Fair value investments | 10.4 | 8.8
Total other asset-backed securities | Vehicle receivables | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Mortgage and asset-backed securities |  |
Investment securities |  |
Fair value investments | 254.2 | 277.6
Carrying Value | 254.2 | 277.6
Mortgage and asset-backed securities | Level 2 |  |
Investment securities |  |
Fair value investments | 254.2 | 277.6
Mortgage and asset-backed securities | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Collateralized loan obligations |  |
Investment securities |  |
Fair value investments | 182.9 | 135.0
Carrying Value | 182.9 | 135.0
Collateralized loan obligations | Level 2 |  |
Investment securities |  |
Fair value investments | 182.9 | 135.0
Collateralized loan obligations | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage and asset-backed securities and collateralized loan obligations |  |
Investment securities |  |
Fair value investments | 437.1 | 412.6
Total mortgage and asset-backed securities and collateralized loan obligations | Level 2 |  |
Investment securities |  |
Fair value investments | 437.1 | 412.6
Total mortgage and asset-backed securities and collateralized loan obligations | Level 3 |  |
Investment securities |  |
Fair value investments | $ 0.0 | $ 0.0

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