Goodwill and Other Intangibles - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill, impairment loss	$ (26)
Amortizable intangible assets related to acquisitions		$ 203	$ 213
Accumulated amortization		59	39
Amortization of intangible assets		$ 20	15	$ 11
Weighted average useful life of finite-lived intangible assets acquired		5 years
Future amortization of intangibles in next year		$ 20
Future amortization of intangibles in year two		20
Future amortization of intangibles in year three		21
Future amortization of intangibles in year four		18
Future amortization of intangibles in year five		17
Future amortization of intangibles after year five		$ 107
Verikai, Inc.
Goodwill [Line Items]
Goodwill, impairment loss			$ (26)