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Municipal Bond Guarantee Insurance - Schedule of Municipal Bond Guarantee Insured Obligations (Details) - BAM $ in Millions | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2021 USD ($) Contract | Dec. 31, 2020 USD ($) Contract | Mar. 31, 2021 USD ($) | Sep. 30, 2019 USD ($)
Guarantor Obligations [Line Items] |  |  |  |
Contracts outstanding | Contract | 12,350 | 10,997 |  |
Remaining weighted average contract period (in years) | 10 years 9 months 18 days | 10 years 8 months 12 days |  |
Principal | $ 89,196.5 | $ 75,287.7 | $ 800.0 | $ 1,100.0
Interest | 41,486.5 | 36,448.8 |  |
Total debt service outstanding | 130,683.0 | 111,736.5 |  |
Gross unearned insurance premiums | $ 266.3 | $ 237.5 |  |

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- Definition Amount of unearned premium revenue under contracts issued by an insurance entity that provide protection to the holder of a financial obligation from a financial loss in the event of a default. + References No definition available. + Details
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