Dispositions - Schedule of Major Classes of Assets and Liabilities Classified as Held for Sale (Details) - USD ($) $ in Millions	Sep. 30, 2025	Jul. 01, 2025	Apr. 01, 2025	Dec. 31, 2024
Investments
Total assets	$ 0			$ 3,092
Liabilities
Total liabilities	0			2,113
Goodwill	$ 3,118			3,245
Disposal Group, Held-for-Sale, Not Discontinued Operations | EVB
Investments
Fixed income securities, at fair value			$ 1,676	1,699
Short-term, at fair value			64	85
Other investments, net			116	122
Total investments			1,856	1,906
Cash			29	0
Deferred policy acquisition costs			525	521
Goodwill			117	111
Other assets			523	554
Total assets			3,050	3,092
Liabilities
Reserve for future policy benefits			1,096	1,085
Contractholder funds			882	890
Other liabilities and accrued expenses			124	138
Total liabilities			2,102	2,113
Fixed income securities, amortized cost			1,765	1,809
Short term, amortized cost			64	$ 85
Goodwill			$ 249
Disposal Group, Held-for-Sale, Not Discontinued Operations | Group Health
Investments
Fixed income securities, at fair value		$ 143
Short-term, at fair value		177
Total investments		320
Cash		88
Deferred policy acquisition costs		1
Other assets		305
Total assets		714
Liabilities
Reserve for future policy benefits		200
Other liabilities and accrued expenses		9
Total liabilities		9
Fixed income securities, amortized cost		142
Short term, amortized cost		177
Goodwill		$ 152