Equity (Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	$ 14,226	$ 8,990	$ 10,025	$ 3,562
OCI before reclassifications	(3,024)	2,951	2,075	9,890
Deferred income tax benefit (expense)	603	(613)	(462)	(2,079)
AOCI before reclassifications, net of income tax	11,805	11,328	11,638	11,373
Amounts reclassified from AOCI	(415)	351	(204)	273
Deferred income tax benefit (expense)	97	(74)	53	(58)
Amounts reclassified from AOCI, net of income tax	(318)	277	(151)	215
Balance, end of period	11,487	11,605	11,487	11,605
Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	10,701	7,509	8,876	2,515
OCI before reclassifications	(2,397)	2,257	(169)	8,594
Deferred income tax benefit (expense)	473	(467)	11	(1,807)
AOCI before reclassifications, net of income tax	8,777	9,299	8,718	9,302
Amounts reclassified from AOCI	(1)	7	73	5
Deferred income tax benefit (expense)	10	(1)	(5)	(1)
Amounts reclassified from AOCI, net of income tax	9	6	68	4
Balance, end of period	8,786	9,305	8,786	9,305
Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	3,988	1,817	1,620	1,382
OCI before reclassifications	(635)	686	2,241	1,303
Deferred income tax benefit (expense)	133	(144)	(471)	(274)
AOCI before reclassifications, net of income tax	3,486	2,359	3,390	2,411
Amounts reclassified from AOCI	(427)	339	(305)	250
Deferred income tax benefit (expense)	90	(72)	64	(53)
Amounts reclassified from AOCI, net of income tax	(337)	267	(241)	197
Balance, end of period	3,149	2,626	3,149	2,626
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(104)	(84)	(97)	(74)
OCI before reclassifications	12	7	3	(7)
Deferred income tax benefit (expense)	(4)	(2)	(2)	2
AOCI before reclassifications, net of income tax	(96)	(79)	(96)	(79)
Amounts reclassified from AOCI	0	0	0	0
Deferred income tax benefit (expense)	0	0	0	0
Amounts reclassified from AOCI, net of income tax	0	0	0	0
Balance, end of period	(96)	(79)	(96)	(79)
Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, beginning of period	(359)	(252)	(374)	(261)
OCI before reclassifications	(4)	1	0	0
Deferred income tax benefit (expense)	1	0	0	0
AOCI before reclassifications, net of income tax	(362)	(251)	(374)	(261)
Amounts reclassified from AOCI	13	5	28	18
Deferred income tax benefit (expense)	(3)	(1)	(6)	(4)
Amounts reclassified from AOCI, net of income tax	10	4	22	14
Balance, end of period	$ (352)	$ (247)	$ (352)	(247)
Accounting Standards Update 2017-12
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI				21
Deferred income tax benefit (expense)				(4)
Amounts reclassified from AOCI, net of income tax				17
Accounting Standards Update 2017-12 | Unrealized Investment Gains (Losses), Net of Related Offsets
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI				(1)
Deferred income tax benefit (expense)				0
Amounts reclassified from AOCI, net of income tax				(1)
Accounting Standards Update 2017-12 | Unrealized Gains (Losses) on Derivatives
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI				22
Deferred income tax benefit (expense)				(4)
Amounts reclassified from AOCI, net of income tax				18
Accounting Standards Update 2017-12 | Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI				0
Deferred income tax benefit (expense)				0
Amounts reclassified from AOCI, net of income tax				0
Accounting Standards Update 2017-12 | Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amounts reclassified from AOCI				0
Deferred income tax benefit (expense)				0
Amounts reclassified from AOCI, net of income tax				$ 0