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Investment Securities - Mortgage-backed Asset Securities (Details) - USD ($) $ in Millions | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Total mortgage-backed securities |  |
Investment securities |  |
Fair value investments | $ 256.5 | $ 199.4
Total mortgage-backed securities | Level 2 |  |
Investment securities |  |
Fair value investments | 256.5 | 199.4
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 | 125.4 | 88.7
Total mortgage-backed securities | FNMA | Level 2 |  |
Investment securities |  |
Fair value investments | 125.4 | 88.7
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 | 90.5 | 70.1
Total mortgage-backed securities | FHLMC | Level 2 |  |
Investment securities |  |
Fair value investments | 90.5 | 70.1
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 | 40.1 | 40.6
Total mortgage-backed securities | GNMA | Level 2 |  |
Investment securities |  |
Fair value investments | 40.1 | 40.6
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 | 256.0 | 199.4
Total mortgage-backed securities | Total agency | Level 2 |  |
Investment securities |  |
Fair value investments | 256.0 | 199.4
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 | 0.5 | 0.0
Total mortgage-backed securities | Non-agency: Residential | Level 2 |  |
Investment securities |  |
Fair value investments | 0.5 | 0.0
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 | 0.5 | 0.0
Total mortgage-backed securities | Total non-agency | Level 2 |  |
Investment securities |  |
Fair value investments | 0.5 | 0.0
Total mortgage-backed securities | Total non-agency | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Total mortgage-backed securities | Collateralized mortgage obligations |  |
Investment securities |  |
Fair value investments | 135.0 |
Total other asset-backed securities |  |
Investment securities |  |
Fair value investments | 21.1 | 19.1
Total other asset-backed securities | Level 2 |  |
Investment securities |  |
Fair value investments | 21.1 | 19.1
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 | 12.3 | 11.3
Total other asset-backed securities | Credit card receivables | Level 2 |  |
Investment securities |  |
Fair value investments | 12.3 | 11.3
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 | 8.8 | 7.8
Total other asset-backed securities | Vehicle receivables | Level 2 |  |
Investment securities |  |
Fair value investments | 8.8 | 7.8
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 | 277.6 | 218.5
Mortgage and asset-backed securities | Level 2 |  |
Investment securities |  |
Fair value investments | 277.6 | 218.5
Mortgage and asset-backed securities | Level 3 |  |
Investment securities |  |
Fair value investments | 0.0 | 0.0
Collateralized loan obligations |  |
Investment securities |  |
Fair value investments | 135.0 | 0.0
Collateralized loan obligations | Level 2 |  |
Investment securities |  |
Fair value investments | 135.0 | 0.0
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 | 412.6 | 218.5
Total mortgage and asset-backed securities and collateralized loan obligations | Level 2 |  |
Investment securities |  |
Fair value investments | 412.6 | 218.5
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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