Segment Information (Total Revenues of Reportable Segments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 4,137	$ 3,606	$ 8,256	$ 6,810
Corporate and Other [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	141	90	582	82
Other Segments | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	2,249	1,965	4,204	3,637
Other Segments | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	392	333	761	653
Other Segments | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	598	507	1,201	992
Other Segments | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	757	711	1,508	1,446
Life Insurance Product Line [Member] | Other Segments | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	1,816	1,642	3,453	3,175
Life Insurance Product Line [Member] | Other Segments | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	366	311	709	607
Life Insurance Product Line [Member] | Other Segments | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	459	371	916	778
Life Insurance Product Line [Member] | Other Segments | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	653	636	1,300	1,303
Nontraditional Long-Duration Contracts [Member] | Other Segments | Americas [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	433	323	751	462
Nontraditional Long-Duration Contracts [Member] | Other Segments | CANADA
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	26	22	52	46
Nontraditional Long-Duration Contracts [Member] | Other Segments | EMEA [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	139	136	285	214
Nontraditional Long-Duration Contracts [Member] | Other Segments | Asia Pacific [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 104	$ 75	$ 208	$ 143