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Transactions With Related Parties (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Jan. 01, 2021	Dec. 31, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Reinsurance recoverable on unpaid and paid losses and LAE	$ 4,314,515	$ 4,041,076		$ 4,500,802	$ 4,363,507	$ 4,303,135	$ 4,346,816
Premia Holdings Ltd. | Barbican Group Holdings Limited
Related Party Transaction [Line Items]
Legacy business, amount of liabilities transferred			$ 380,000
Reinsurance recoverable on unpaid and paid losses and LAE	0			199,800
Funds held liability	$ 9,900			$ 149,600

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Transfer Of Legacy Business On Acquisition

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- Definition

Amount of funds held as security for payments to be received under reinsurance contracts.

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- Definition

Amount, after valuation allowance, recoverable under reinsurance contracts. Examples include, but are not limited to, settled and unsettled claims, incurred but not reported losses, loss adjustment expense, policy benefits and policy reserves. Excludes premiums paid under reinsurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21412-158489

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 310
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99404803&loc=d3e21409-158489

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=99397103&loc=d3e6824-158387

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 825
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=123600520&loc=SL75241803-196195

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