XML 89 R66.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Reinsurance - Quota Share Agreement Terms (Details) | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023
2020 QSR and 2021 QSR - 2021 NIW |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 17.50%
Annual Loss Ratio to Exhaust Profit Commission |  | 61.90%
Cede rate, option 1 |  | 14.50%
Cede rate, option 2 |  | 12.00%
2021 QSR and 2022 QSR - 2021 NIW |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 12.50%
Annual Loss Ratio to Exhaust Profit Commission |  | 57.50%
Cede rate, option 1 |  | 10.50%
Cede rate, option 2 |  | 8.00%
2021 QSR and 2022 QSR - 2022 NIW |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 15.00%
Annual Loss Ratio to Exhaust Profit Commission |  | 57.50%
Cede rate, option 1 |  | 12.50%
Cede rate, option 2 |  | 10.00%
2022 QSR and 2023 QSR - 2022 NIW |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 15.00%
Annual Loss Ratio to Exhaust Profit Commission |  | 62.00%
Cede rate, option 1 |  | 12.50%
Cede rate, option 2 |  | 10.00%
2022 QSR and 2023 QSR - 2023 NIW |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 15.00%
Annual Loss Ratio to Exhaust Profit Commission |  | 62.00%
Cede rate, option 1 |  | 12.50%
Cede rate, option 2 |  | 10.00%
QSR 2023 - 2023 NIW |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 10.00%
Annual Loss Ratio to Exhaust Profit Commission |  | 58.50%
Cede rate, option 1 |  | 8.00%
Cede rate, option 2 |  | 7.00%
Credit Union QSR Transaction |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % |  | 65.00%
Annual Loss Ratio to Exhaust Profit Commission |  | 50.00%
QSR 2024 - 2024 NIW | Forecast |  |
Effects of Reinsurance [Line Items] |  |
Quota Share % | 30.00% |
Annual Loss Ratio to Exhaust Profit Commission | 56.00% |

X
- Definition Reinsurance, Quota Share Reinsurance Agreement, Terms, Ceding Rate, Percent, Option One + References No definition available. + Details
Name: | mtg_ReinsuranceQuotaShareReinsuranceAgreementTermsCedingRatePercentOptionOne
Namespace Prefix: | mtg_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reinsurance, Quota Share Reinsurance Agreement, Terms, Ceding Rate, Percent, Option Two + References No definition available. + Details
Name: | mtg_ReinsuranceQuotaShareReinsuranceAgreementTermsCedingRatePercentOptionTwo
Namespace Prefix: | mtg_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reinsurance, Quota Share Reinsurance Agreement, Terms, Quota Share, Percent + References No definition available. + Details
Name: | mtg_ReinsuranceQuotaShareReinsuranceAgreementTermsQuotaSharePercent
Namespace Prefix: | mtg_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_EffectsOfReinsuranceLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio of non-life losses and loss expenses to non-life net premiums earned. + References No definition available. + Details
Name: | us-gaap_LossRatio
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction2020And20212021NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction2021And20222021NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction2021And20222022NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction2022And20232022NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction2022And20232023NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction20232023NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_CreditUnionQuotaShareReinsuranceTransactionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CededCreditRiskAxis=mtg_QuotaShareReinsuranceTransaction20242024NIWMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |