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Municipal Bond Guarantee Insurance - Schedule of Municipal Bond Guarantee Insured Obligations (Details) - BAM $ in Millions | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Mar. 31, 2022 USD ($) Contract | Dec. 31, 2021 USD ($) Contract | Jan. 31, 2021 USD ($)
Guarantor Obligations [Line Items] |  |  |
Contracts outstanding | Contract | 12,611 | 12,350 |
Remaining weighted average contract period outstanding (in years) | 10 years 9 months 18 days | 10 years 9 months 18 days |
Principal | $ 91,609.8 | $ 89,196.5 | $ 805.5
Interest | 42,353.7 | 41,486.5 |
Total debt service outstanding | 133,963.5 | 130,683.0 |
Total gross unearned insurance premiums | $ 267.3 | $ 266.3 |

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