Insurance (Liabilities for Unpaid Claims - Methodology) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-duration Insurance Contract, Discounted Liability, Discount	$ 1,326
Short-Duration Insurance Contract, Discounted Liability, Interest Accretion, Statement of Financial Position [Extensible Enumeration]	Policyholder benefits and claims	Policyholder benefits and claims	Policyholder benefits and claims
Group Long-Term Disability
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contracts, Discounted Liabilities, Amount	$ 6,500	$ 6,200
Short-duration Insurance Contract, Discounted Liability, Discount	1,200	1,100
Short-duration Insurance Contracts, Discounted Liabilities, Interest Accretion	$ 461	518	$ 452
Group Long-Term Disability | Minimum
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contract, Discounted Liability, Discount Rate	3.00%
Group Long-Term Disability | Maximum
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contract, Discounted Liability, Discount Rate	8.00%
Group Life - Term | Asia
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contracts, Discounted Liabilities, Amount	$ 1,300	1,200
Short-duration Insurance Contract, Discounted Liability, Discount	118	73
Short-duration Insurance Contracts, Discounted Liabilities, Interest Accretion	$ 22	$ 22	$ 24
Group Life - Term | Minimum | Asia
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contract, Discounted Liability, Discount Rate	1.00%
Group Life - Term | Maximum | Asia
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contract, Discounted Liability, Discount Rate	7.00%