v3.26.1
Future Policy Benefits (Assumption Explanations) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Mar. 31, 2025
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 $ 15,000 $ 14,700
Future Policy Benefits Actual To Expected Variance (6,000) (49,000)
Impact Of Updating Discount Rate Recognized In OCI (305,000) 70,000
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 3,600 3,400
Future Policy Benefits Actual To Expected Variance (4) 0
Impact Of Updating Discount Rate Recognized In OCI (54,000) 27,000
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 2,000 1,600
Future Policy Benefits Actual To Expected Variance 10,000 9,000
Impact Of Updating Discount Rate Recognized In OCI 70,000 48,000
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 5,500 5,000
Future Policy Benefits Actual To Expected Variance 8,000 (16,000)
Impact Of Updating Discount Rate Recognized In OCI (68,000) 50,000
Insurance, Other | Americas [Member]    
Liability for Future Policy Benefit, by Product Segment [Line Items]    
Net Liability For Future Policy Benefits At Original Discount Rate 11,200 10,200
Future Policy Benefits Actual To Expected Variance (12) (1)
Impact Of Updating Discount Rate Recognized In OCI (166) (93)
Insurance, Other | CANADA    
Liability for Future Policy Benefit, by Product Segment [Line Items]    
Net Liability For Future Policy Benefits At Original Discount Rate 4,600 4,400
Future Policy Benefits Actual To Expected Variance (1) 0
Impact Of Updating Discount Rate Recognized In OCI (35) (49)
Insurance, Other | EMEA [Member]    
Liability for Future Policy Benefit, by Product Segment [Line Items]    
Net Liability For Future Policy Benefits At Original Discount Rate 10,600 7,100
Future Policy Benefits Actual To Expected Variance 11 3
Impact Of Updating Discount Rate Recognized In OCI 421 127
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 21,400 14,400
Future Policy Benefits Actual To Expected Variance 1 3
Impact Of Updating Discount Rate Recognized In OCI $ (619) $ (365)