Fair Value Measurements - Fair Values of Separate Account Assets (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Guaranteed separate accounts	$ 585
Non-guaranteed separate accounts	5,936
Subtotal	6,521
Guaranteed separate accounts, including held for sale assets		$ 503
Non-guaranteed separate accounts, including held for sale assets		7,870
Subtotal, including held for sale assets		8,373
Non-guaranteed separate accounts priced at NAV as a practical expedient	757
Non-guaranteed separate accounts priced at NAV as a practical expedient, including held for sale assets		842
Total, including held for sale assets		9,215
Separate account assets of business classified as held for sale		(878)
Separate account assets	7,278	8,337
Pension Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-guaranteed separate accounts	4,000
Non-guaranteed separate accounts, including held for sale assets		4,500
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Guaranteed separate accounts	203
Non-guaranteed separate accounts	211
Subtotal	414
Guaranteed separate accounts, including held for sale assets		227
Non-guaranteed separate accounts, including held for sale assets		1,130
Subtotal, including held for sale assets		1,357
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Guaranteed separate accounts	382
Non-guaranteed separate accounts	5,522
Subtotal	5,904
Guaranteed separate accounts, including held for sale assets		276
Non-guaranteed separate accounts, including held for sale assets		6,406
Subtotal, including held for sale assets		6,682
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Guaranteed separate accounts	0
Non-guaranteed separate accounts	203
Subtotal	203
Guaranteed separate accounts, including held for sale assets		0
Non-guaranteed separate accounts, including held for sale assets		334
Subtotal, including held for sale assets		334
Significant Unobservable Inputs (Level 3) | Pension Plans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Non-guaranteed separate accounts	$ 200
Non-guaranteed separate accounts, including held for sale assets		$ 300