Segment Information (Reconciliation of Assets from Segment to Consolidated) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 84,656	$ 76,731
Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	45,504	44,470
Canada Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,695	4,425
EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	12,055	10,534
Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	12,496	9,357
Corporate And Other Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	9,906	7,945
Life Insurance Product Line [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	20,071	19,353
Life Insurance Product Line [Member] | Canada Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,682	4,361
Life Insurance Product Line [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	4,763	4,032
Life Insurance Product Line [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	8,197	6,800
Insurance, Other [Member] | Americas [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	25,433	25,117
Insurance, Other [Member] | Canada Segment Reporting Information [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	13	64
Insurance, Other [Member] | EMEA [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	7,292	6,502
Insurance, Other [Member] | Asia Pacific [Member]
Segment Reporting, Asset Reconciling Item [Line Items]
Total assets	$ 4,299	$ 2,557