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/2009/role/commonPracticeRef
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The amount of cash, securities, or other assets held by a third-party trustee pursuant to the terms of an agreement which assets are available to be used by beneficiaries to that agreement only within the specific terms thereof and which agreement is expected to terminate within one year of the balance sheet date (or operating cycle, if longer) at which time the assets held-in-trust will be released or forfeited.

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The cash inflow from issuance of preferred stock that is classified as callable.

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Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

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Other Significant Transactions [Line Items]

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Significant Transactions - Outrigger Re (Details) - USD ($) $ in Millions			3 Months Ended	12 Months Ended
	Dec. 20, 2022	Jan. 01, 2021	Dec. 31, 2022	Dec. 31, 2022
Ark
Other Significant Transactions [Line Items]
Ownership interest after all transactions (as a percent)		72.00%
Outrigger Re
Other Significant Transactions [Line Items]
Issuance of redeemable preference shares	$ 250.0
Outrigger Re \| Cash and Short Term Investments
Other Significant Transactions [Line Items]
Investment owned, balance			$ 203.7	$ 203.7
Assets held in trust, expenses				$ 1.3
Outrigger Re
Other Significant Transactions [Line Items]
Purchase price			$ 205.0
Ownership interest after all transactions (as a percent)			100.00%