Separate Accounts (Separate Account Assets) (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Fair Value, Separate Account Investment [Line Items]
Separate account assets	$ 194,761	$ 193,372
U.S. Treasury securities and obligations of U.S. government authorities and agencies
Fair Value, Separate Account Investment [Line Items]
Separate account assets	4,500	4,674
Obligations of U.S. states and their political subdivisions
Fair Value, Separate Account Investment [Line Items]
Separate account assets	2,444	2,224
Foreign government bonds
Fair Value, Separate Account Investment [Line Items]
Separate account assets	105	93
U.S. corporate securities
Fair Value, Separate Account Investment [Line Items]
Separate account assets	11,820	11,440
Foreign corporate securities
Fair Value, Separate Account Investment [Line Items]
Separate account assets	3,056	3,010
Asset-backed securities
Fair Value, Separate Account Investment [Line Items]
Separate account assets	1,935	1,283
Mortgage-backed securities
Fair Value, Separate Account Investment [Line Items]
Separate account assets	13,327	14,144
Equity
Fair Value, Separate Account Investment [Line Items]
Separate account assets	89,861	90,180
Fixed Income
Fair Value, Separate Account Investment [Line Items]
Separate account assets	32,399	33,828
Other
Fair Value, Separate Account Investment [Line Items]
Separate account assets	6,198	5,439
Equity securities
Fair Value, Separate Account Investment [Line Items]
Separate account assets	5,196	4,845
Commercial mortgage and other loans
Fair Value, Separate Account Investment [Line Items]
Separate account assets	55	54
Other invested assets
Fair Value, Separate Account Investment [Line Items]
Separate account assets	19,552	19,352
Short-term investments
Fair Value, Separate Account Investment [Line Items]
Separate account assets	1,450	1,137
Cash and cash equivalents
Fair Value, Separate Account Investment [Line Items]
Separate account assets	$ 2,863	$ 1,669