Insurance (Liabilities for Unpaid Claims - Methodology) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-duration Insurance Contract, Discounted Liability, Discount	$ 1,205
Group Long-Term Disability
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contracts, Discounted Liabilities, Amount	6,200	$ 6,000
Short-duration Insurance Contract, Discounted Liability, Discount	1,100	1,200
Short-duration Insurance Contracts, Discounted Liabilities, Interest Accretion	$ 518	452	$ 470
Group Long-Term Disability | Minimum
Liability for Claims and Claims Adjustment Expense [Line Items]
Short-Duration Contract, Discounted Liability, Discount Rate	2.00%
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	$ 1,200	1,000
Short-duration Insurance Contract, Discounted Liability, Discount	73	68
Short-duration Insurance Contracts, Discounted Liabilities, Interest Accretion	$ 22	$ 24	$ 20
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%