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Statutory Information - Narrative (Details) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2020 USD ($) | Dec. 31, 2020 USD ($) jurisdiction | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($)
Statutory capital requirements [Abstract] |  |  |  |
Percentage of premiums earned required to be maintained as contingency loss reserves (in hundredths) |  | 50.00% |  |
Period that contingency loss reserves must be held (in years) |  | 10 years |  |
Percentage of net premiums earned that incurred losses must exceed to enable early withdrawals from contingency loss reserves (in hundredths) |  | 35.00% |  |
Number of jurisdictions with risk-to-capital requirements | jurisdiction |  | 16 |  |
Maximum permitted risk-to-capital ratio commonly applied |  | 25 to 1 |  |
Risk to capital ratio of combined insurance operations at end of period |  | 9.1 to 1 |  |
Risk-to-capital ratio on combined insurance operations |  | 9.1 |  |
Statutory net income (loss) |  | $ 65,201,000 | $ 305,857,000 | $ 375,484,000
Statutory policyholders' surplus |  | $ 1,339,509,000 | 1,619,069,000 | 1,683,058,000
Maximum |  |  |  |
Statutory capital requirements [Abstract] |  |  |  |
Risk to capital ratio |  | 25 |  |
Mortgage Guaranty Insurance Corporation |  |  |  |
Statutory capital requirements [Abstract] |  |  |  |
Contingency reserve withdrawal |  | $ 30,400,000 |  |
Risk to capital ratio at end of period |  | 9.2 to 1 |  |
Risk to capital ratio |  | 9.2 |  |
Amount of policyholders position above or below required MPP |  | $ 3,200,000,000 |  |
Amount of required MPP |  | 1,700,000,000 |  |
Dividends paid to the parent company |  | $ 390,000,000 | $ 280,000,000 | $ 220,000,000
Dividend to parent, distribution of interest in 9% Debentures | $ 139,500,000 |  |  |
Percentage of statutory policyholders surplus used to determine maximum allowable dividends |  | 10.00% |  |
Adjusted statutory net income measurement period |  | 3 years |  |
Adjusted statutory net income dividend payment measurement period |  | 2 years |  |
Reduction in statutory net income due to increase in contingency reserve |  | $ 559,000,000 |  |
Statutory net income (loss) |  | (643,000,000) |  |
Statutory policyholders' surplus |  | 1,336,000,000 |  |
Realized statutory loss on merger of affiliate, eliminated in consolidation |  | $ 692,000,000 |  |

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- Definition The amount by which the entity's policyholders position (the insurer's net worth or surplus, contingency reserve and a portion of the reserves for unearned premiums) was above or below the required regulatory minimum of the entity's domiciliary state. + References No definition available. + Details
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- Definition The amount of minimum policyholder position (MPP) required by the entity's domiciliary state. + References No definition available. + Details
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- Definition Amount of withdrawal from the contingency reserve, subject to regulatory approval, for the period. + References No definition available. + Details
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- Definition Amount of distribution, in form of a dividend, to holding company of interest in convertible junior subordinated debentures. + References No definition available. + Details
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- Definition The number of jurisdictions that require a mortgage insurer to maintain a minimum amount of statutory capital relative to the risk in force (or a similar measure) in order for the mortgage insurer to continue to write new business. This is generally referred to as a risk-to-capital requirement. + References No definition available. + Details
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X
- Definition The percentage of net premiums earned that incurred losses must exceed in a calendar year to allow a mortgage guaranty insurance company to make early withdrawals from the contingency loss reserve with regulatory approval. + References No definition available. + Details
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- Definition The percentage of premiums earned that is required to be maintained as contingency loss reserves by mortgage guaranty insurance companies under statutory accounting practices. + References No definition available. + Details
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- Definition The percentage of statutory policyholders' surplus, as defined, as of the preceding calendar year end which is used in the determination of the maximum allowable dividends that the insurance subsidiaries may pay in any twelve-month period without regulatory approval by the Office of the Commissioner of Insurance of the State of Wisconsin. + References No definition available. + Details
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- Definition The length of time during which contingency loss reserves cannot be withdrawn under statutory accounting practices except as permitted by insurance regulations. + References No definition available. + Details
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- Definition Realized statutory loss from affiliate due to recognition of cumulative unrealized losses on merger/disposition of affiliate. + References No definition available. + Details
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- Definition The entity's risk-to-capital ratio as of the end of the reporting period. + References No definition available. + Details
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- Definition The risk-to-capital ratio of the entity's combined insurance operations as of the end of the reporting period. + References No definition available. + Details
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- Definition Statutory Accounting Practices, Statutory Amount Available For Dividend Payments Without Regulatory Approval, Measurement, Measurement Period + References No definition available. + Details
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- Definition Statutory Accounting Practices, Statutory Amount Available for Dividend Payments without Regulatory Approval, Measurement, Dividend Payment Period + References No definition available. + Details
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- Definition Statutory Accounting Practices, Statutory Net Income, Adjustment + References No definition available. + Details
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- References No definition available. + Details
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- Definition Statutory Capital Requirements, Risk To Capital Ratio + References No definition available. + Details
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- Definition Statutory Capital Requirements, Risk To Capital Ratio For Combined Insurance Operations + References No definition available. + Details
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- Definition This element represents disclosure of the total aggregate cash dividends paid to the entity by consolidated subsidiaries, by unconsolidated subsidiaries, and by 50% or less owned persons accounted for using the equity method. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-04(b)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24072-122690 + Details
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- Definition For insurance companies, a description of the minimum regulatory capital requirements imposed by state insurance regulators, and restrictions on dividend payments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 505 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6486098&loc=d3e24708-158529 + Details
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- Definition The amount of statutory capital and surplus (stockholders' equity) as of the balance sheet date using prescribed or permitted statutory accounting practices (rather than GAAP, if different) of the state or country. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(23)(c)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 505 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6486098&loc=d3e24708-158529 + Details
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- Definition Amount of net income for the period determined using accounting principles prescribed or permitted by insurance regulators. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(23)(c)) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 + Details
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