Future Policy Benefits (Assumption Explanations) (Details) - Other Segments - USD ($)	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Life Insurance Product Line [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Changes In Cash Flow Assumptions	$ 85,000,000	$ 269,000,000
Life Insurance Product Line [Member] | Americas [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	12,000,000,000	11,000,000,000
Future Policy Benefits Actual To Expected Variance	(5,000,000)	(92,000,000)
Impact Of Updating Discount Rate Recognized In OCI	$ 1,000,000	$ (5,200,000)
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	7.2% increase	3.3% increase
Future Policy Benefits Actual To Expected Variance Increase Decrease	—	0.9% increase
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	9.2% decrease	49 % decrease
Changes In Cash Flow Assumptions	$ 17,000,000	$ 130,000,000
Change In Cash Flow Assumptions Increase Decrease	0.2% increase	1.2% increase
Life Insurance Product Line [Member] | CANADA
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	$ 3,400,000,000	$ 3,200,000,000
Future Policy Benefits Actual To Expected Variance	(5,000,000)	(27,000,000)
Impact Of Updating Discount Rate Recognized In OCI	$ 267,000,000	$ (1,500,000)
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	3.5% increase	6.2% decrease
Future Policy Benefits Actual To Expected Variance Increase Decrease	0.2% increase	0.8% increase
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	8.0% decrease	43.9% decrease
Changes In Cash Flow Assumptions	$ 12,000,000	$ 6,000,000
Change In Cash Flow Assumptions Increase Decrease	0.4% increase	0.2% increase
Life Insurance Product Line [Member] | EMEA [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	$ 1,300,000,000	$ 1,100,000,000
Future Policy Benefits Actual To Expected Variance	9,000,000	(11,000,000)
Impact Of Updating Discount Rate Recognized In OCI	$ (88,000,000)	$ (345,000,000)
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	9.8% increase	10.2% decrease
Future Policy Benefits Actual To Expected Variance Increase Decrease	0.7% increase	0.9% decrease
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	7.3% decrease	28.2% decrease
Changes In Cash Flow Assumptions	$ 47,000,000	$ 13,000,000
Change In Cash Flow Assumptions Increase Decrease	3.9% increase	1.1% increase
Life Insurance Product Line [Member] | Asia Pacific [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	$ 4,500,000,000	$ 4,100,000,000
Future Policy Benefits Actual To Expected Variance	(49,000,000)	27,000,000
Impact Of Updating Discount Rate Recognized In OCI	$ 233,000,000	$ (903,000,000)
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	5.5% increase	1.9% increase
Future Policy Benefits Actual To Expected Variance Increase Decrease	1.1% decrease	0.7% decrease
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	5.4% decrease	22.4% decrease
Changes In Cash Flow Assumptions	$ 9,000,000	$ 120,000,000
Change In Cash Flow Assumptions Increase Decrease	0.2% increase	3% increase
Insurance, Other
Liability for Future Policy Benefit, by Product Segment [Line Items]
Changes In Cash Flow Assumptions	$ 78,000,000	$ 3,000,000
Insurance, Other | Americas [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	4,900,000,000	4,200,000,000
Future Policy Benefits Actual To Expected Variance	8,000,000	23,000,000
Impact Of Updating Discount Rate Recognized In OCI	$ 119,000,000	$ 928,000,000
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	18.2% increase	4.4% decrease
Future Policy Benefits Actual To Expected Variance Increase Decrease	0.2% decrease	0.5% decrease
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	2.9% decrease	21.1% decrease
Changes In Cash Flow Assumptions	$ (22,000,000)	$ (3,000,000)
Change In Cash Flow Assumptions Increase Decrease	0.5% decrease	0.1% decrease
Insurance, Other | CANADA
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	$ 26,000,000,000	$ 53,000,000,000
Future Policy Benefits Actual To Expected Variance	8,000,000	9,000,000
Impact Of Updating Discount Rate Recognized In OCI	$ (1,000,000)	$ 15,000,000
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	50.9% decrease	17.2% decrease
Future Policy Benefits Actual To Expected Variance Increase Decrease	15.1% decrease	14.1% decrease
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	1.9% increase	23.4% decrease
Changes In Cash Flow Assumptions	$ (22,000,000)	$ 0
Change In Cash Flow Assumptions Increase Decrease	41.5% decrease	—
Insurance, Other | EMEA [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	$ 5,900,000,000	$ 5,000,000,000
Future Policy Benefits Actual To Expected Variance	(13,000,000)	(9,000,000,000)
Impact Of Updating Discount Rate Recognized In OCI	$ (67,000,000)	$ (1,600,000)
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	7.2% increase	19.6% decrease
Future Policy Benefits Actual To Expected Variance Increase Decrease	0.2% decrease	0.1% decrease
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	1.2% decrease	29.2% decrease
Changes In Cash Flow Assumptions	$ (34,000,000)	$ 0
Change In Cash Flow Assumptions Increase Decrease	0.6% decrease	—
Insurance, Other | Asia Pacific [Member]
Liability for Future Policy Benefit, by Product Segment [Line Items]
Net Liability For Future Policy Benefits At Original Discount Rate	$ 5,700,000,000	$ 4,500,000,000
Future Policy Benefits Actual To Expected Variance	(2,000,000)	1,000,000
Impact Of Updating Discount Rate Recognized In OCI	$ 359,000,000	$ 311,000,000
Net Liability For Future Policy Benefits At Original Discount Rate Increase Decrease	14.4% increase	10.4% decrease
Future Policy Benefits Actual To Expected Variance Increase Decrease	—	—
Impact Of Updating Discount Rate Recognized In OCI Increase Decrease	7.2% decrease	6.5% decrease
Changes In Cash Flow Assumptions	$ 0	$ 0
Change In Cash Flow Assumptions Increase Decrease	—	—