Segment Information - Segment Revenue by Country of Domicile (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 1,373	$ 723	$ 848
Subtotal
Segment Reporting Information [Line Items]
Revenues	1,267	887	960
U.S. | Subtotal
Segment Reporting Information [Line Items]
Revenues	1,064	727	762
Bermuda | Subtotal
Segment Reporting Information [Line Items]
Revenues	166	129	153
U.K. | Subtotal
Segment Reporting Information [Line Items]
Revenues	36	32	42
Other | Subtotal
Segment Reporting Information [Line Items]
Revenues	$ 1	$ (1)	$ 3