Significant Transactions - Outrigger Re (Details) - USD ($) $ in Millions		3 Months Ended
Dec. 20, 2022	Dec. 31, 2022
Outrigger Re
Other Significant Transactions [Line Items]
Issuance of redeemable preference shares	$ 250.0
Outrigger Re
Other Significant Transactions [Line Items]
Ownership interest after all transactions (as a percent)		100.00%
Purchase price		$ 205.0

Amount of consideration transferred in asset acquisition. Includes, but is not limited to, cash, liability incurred by acquirer, and equity interest issued by acquirer.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 805
-SubTopic 50
-Name Accounting Standards Codification
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-Publisher FASB
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Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
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-Name Accounting Standards Codification
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Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 805
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Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
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