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Reinsurance - Variable Interest Entity (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2020 | Dec. 31, 2019 | Oct. 30, 2020
Home Re special purpose insurers |  |  |
Effects of Reinsurance [Line Items] |  |  |
Amortization period excess of loss reinsurance coverage | 10 years |  |
Term of mortgage insurance-linked notes | 10 years |  |
Remaining First Layer Retention | $ 351,043 | $ 353,415 |
Remaining Excess of Loss Reinsurance Coverages | $ 426,489 | 531,978 |
Percent of total trust assets invested in cash or direct U.S. federal government obligations | 99.50% |  |
Home Re special purpose insurers | Subsequent Event |  |  |
Effects of Reinsurance [Line Items] |  |  |
Remaining Excess of Loss Reinsurance Coverages |  |  | $ 412,900
Home Re 2018-1 |  |  |
Effects of Reinsurance [Line Items] |  |  |
Remaining First Layer Retention | $ 166,246 | 167,779 |
Remaining Excess of Loss Reinsurance Coverages | 218,343 | 260,957 |
Total VIE Assets | 218,343 | 269,451 |
Home Re 2019-1 |  |  |
Effects of Reinsurance [Line Items] |  |  |
Remaining First Layer Retention | 184,797 | 185,636 |
Remaining Excess of Loss Reinsurance Coverages | 208,146 | 271,021 |
Total VIE Assets | $ 208,146 | $ 283,150 |

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