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Statutory Information - Narrative (Details) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2020 USD ($) subsidiary | Dec. 31, 2019 USD ($)
Bermuda |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Required statutory capital and surplus | [1] | $ 6,431,413 | $ 5,492,968
Ireland |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Number Of Subsidiaries | subsidiary |  | 3 |
Required statutory capital and surplus | [1] | $ 701,161 | 542,703
United States |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Required statutory capital and surplus | [1] | $ 1,644,324 | $ 1,697,640
Mortgage | North Carolina or Wisconsin |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Required contingency loss reserve as a percentage of net earned premiums |  | 50.00% |
Withdrawal restriction period |  | 10 years |
Withdrawal restriction period, with prior approval |  | 35.00% |
Maximum risk to capital ratio |  | 2500.00% |
United Guaranty Residential Insurance Company [Member] | North Carolina |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Dividends available for payment in 2020, total |  | $ 143,100 |
Arch Re US | United States |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Dividends available for payment in 2020, total |  | $ 147,600 |
Arch Re Bermuda | Bermuda |  |  |
Statutory Accounting Practices [Line Items] |  |  |
Dividends, percentage permitted |  | 25.00% |
Dividend required notice period |  | seven days |
Dividends available for payment in 2021 without prior regulatory approval |  | $ 3,800,000 |
[1] | Such amounts include ownership interests in affiliated insurance and reinsurance subsidiaries.

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- Definition The percentage of total statutory capital and surplus (as shown on its previous financial year's statutory balance sheet) which may be paid out as dividends without the requirement to file an affadavit with the regulatory body stating that the Company will continue to meet required margins. + References No definition available. + Details
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- Definition Amount of dividends available for payment after computation of statutory restrictions on capital surplus. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(e)) -URI http://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 + Details
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