Investments (Net Investment Income) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Net Investment Income [Line Items]
Less: Investment expenses	$ 232	$ 236	$ 469	$ 560
Net investment income	5,280	4,087	10,594	7,148
Securities Investment
Net Investment Income [Line Items]
Gross Investment Income, Operating	5,134	3,505	10,478	8,030
Net investment income	4,902	3,269	10,009	7,470
Fixed Maturity Securities
Net Investment Income [Line Items]
Gross Investment Income, Operating	2,739	2,787	5,492	5,662
Equity Securities
Net Investment Income [Line Items]
Gross Investment Income, Operating	9	11	20	25
FVO Securities (1)
Net Investment Income [Line Items]
Net investment income	50	114	86	36
Mortgage loans
Net Investment Income [Line Items]
Gross Investment Income, Operating	885	862	1,748	1,746
Policy loans
Net Investment Income [Line Items]
Gross Investment Income, Operating	120	124	241	250
Real Estate and Real Estate Joint Ventures
Net Investment Income [Line Items]
Gross Investment Income, Operating	205	102	381	267
Other limited partnership interests
Net Investment Income [Line Items]
Net investment income	1,047	(607)	2,329	(287)
Cash, cash equivalents and short-term investments
Net Investment Income [Line Items]
Gross Investment Income, Operating	24	52	49	144
Operating joint ventures
Net Investment Income [Line Items]
Gross Investment Income, Operating	15	31	38	56
Other Investments
Net Investment Income [Line Items]
Gross Investment Income, Operating	40	29	94	131
Unit-linked investments
Net Investment Income [Line Items]
Net investment income	378	818	585	(322)
Trading Securities, Change in Unrealized Holding Gain (Loss)	$ 347	$ 766	$ 549	$ (322)