Income Taxes - Income before taxes by jurisdiction (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Line Items]
Income (loss) before income taxes	$ 4,674	$ 3,570	$ 1,562
Bermuda
Income Tax Disclosure [Line Items]
Income (loss) before income taxes	2,611	2,099	986
United States
Income Tax Disclosure [Line Items]
Income (loss) before income taxes	1,438	1,239	401
Other
Income Tax Disclosure [Line Items]
Income (loss) before income taxes	$ 625	$ 232	$ 175