Held-For-Sale Classification - Narrative (Details) - Assets held-for-sale € in Millions, shares in Millions, $ in Millions	Nov. 01, 2023 USD ($) shares	Oct. 31, 2023 EUR (€)	May 22, 2023 USD ($) shares	Sep. 04, 2023 USD ($)	Dec. 31, 2022 USD ($)
Laya and Other | Subsequent event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration for divestiture of business | €		€ 650
Validus Re
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration for divestiture of business			$ 2,700
Share consideration received on transaction (in shares) | shares			1.3
Reimbursement to be received					$ 400
Reserve balance					$ 3,043
Expected premium to be paid				$ 80
Validus Re | Subsequent event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration for divestiture of business	$ 2,700
Share consideration received on transaction (in shares) | shares	1.3
Value of share consideration received on transaction	$ 275