Fair Value (Unobservable Input Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Residential mortgage loans - FVO
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 180	$ 276	$ 188	$ 299
Total realized/unrealized gains (losses) included in net income (loss)	1	4	3	6
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	0	0	0	0
Sales	(2)	(9)	(7)	(25)
Issuances	0	0	0	0
Settlements	(4)	(9)	(9)	(18)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	175	262	175	262
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	1	0	1
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	1	0	1
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Net Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	46	69	(12)	104
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(154)		899
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	1,039	(69)	(146)	(225)
Total realized/unrealized gains (losses) included in net income (loss)	38	75	112	125
Total realized/unrealized gains (losses) included in AOCI	(166)	136	991	223
Purchases	0	4	0	4
Sales	0	0	0	0
Issuances	0	(1)	0	(1)
Settlements	(113)	(40)	(159)	(21)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	798	105	798	105
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	46	69	(12)	104
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(154)		899
Net Embedded Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	366	(146)	(1,056)	46
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(2)		(6)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	(2,232)	(605)	(742)	(739)
Total realized/unrealized gains (losses) included in net income (loss)	371	(146)	(1,051)	47
Total realized/unrealized gains (losses) included in AOCI	(1)	(15)	(6)	(8)
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	(63)	(69)	(126)	(135)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	(1,925)	(835)	(1,925)	(835)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	366	(146)	(1,056)	46
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(2)		(6)
Corporate fixed maturity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	19,809	10,962	14,229	10,467
Total realized/unrealized gains (losses) included in net income (loss)	(21)	0	(68)	6
Total realized/unrealized gains (losses) included in AOCI	1,321	226	(266)	595
Purchases	1,158	705	2,809	1,030
Sales	(437)	(264)	(562)	(351)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	149	104	5,101	245
Transfers out of Level 3	(1,247)	(126)	(511)	(385)
Balance, end of period	20,732	11,607	20,732	11,607
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(13)	(3)	(36)	(4)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	1,313		(290)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(13)	(3)	(36)	(4)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	1,313		(290)
Foreign government
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	104	157	117	138
Total realized/unrealized gains (losses) included in net income (loss)	(1)	0	(6)	1
Total realized/unrealized gains (losses) included in AOCI	2	(1)	0	(2)
Purchases	9	2	10	3
Sales	(3)	(5)	(4)	(6)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	1	12	1	13
Transfers out of Level 3	(55)	(22)	(61)	(4)
Balance, end of period	57	143	57	143
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	1	(1)	1
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	2		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	1	1	(1)	1
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	2		0
Structured Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	4,014	4,069	4,458	4,266
Total realized/unrealized gains (losses) included in net income (loss)	4	12	14	25
Total realized/unrealized gains (losses) included in AOCI	206	41	(109)	62
Purchases	1,307	401	1,691	592
Sales	(219)	(205)	(433)	(335)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	143	6	156	7
Transfers out of Level 3	(78)	(169)	(400)	(462)
Balance, end of period	5,377	4,155	5,377	4,155
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	13	11	23	25
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	200		(106)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	13	11	23	25
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	200		(106)
Municipals
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	0	0	7	0
Total realized/unrealized gains (losses) included in net income (loss)	0	0	0	0
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	0	7	0	7
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	(7)	0
Balance, end of period	0	7	0	7
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	372	434	430	419
Total realized/unrealized gains (losses) included in net income (loss)	14	(2)	(13)	28
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	7	41	9	48
Sales	(2)	(16)	(34)	(38)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	(18)	0	(19)	0
Balance, end of period	373	457	373	457
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	12	(3)	(12)	15
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	12	(3)	(12)	15
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Unit-linked and FVO Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	517	457	625	405
Total realized/unrealized gains (losses) included in net income (loss)	56	10	(24)	29
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	14	38	25	70
Sales	(4)	(5)	(101)	(7)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	17	1	155	2
Transfers out of Level 3	(11)	(7)	(91)	(5)
Balance, end of period	589	494	589	494
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	56	10	(25)	29
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	56	10	(25)	29
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Short-term Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	368	138	32	33
Total realized/unrealized gains (losses) included in net income (loss)	0	0	0	1
Total realized/unrealized gains (losses) included in AOCI	2	0	(3)	(1)
Purchases	1	15	2	119
Sales	(17)	(25)	(16)	(31)
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	4	2	9	2
Transfers out of Level 3	(351)	(7)	(17)	0
Balance, end of period	7	123	7	123
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	1
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	1		(3)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	1
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	1		(3)
Other Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	475	168	455	39
Total realized/unrealized gains (losses) included in net income (loss)	(7)	0	(3)	0
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	23	64	39	193
Sales	0	0	0	0
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance, end of period	491	232	491	232
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(5)	0	0	0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(5)	0	0	0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Separate Accounts
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	1,046	897	980	937
Total realized/unrealized gains (losses) included in net income (loss)	9	2	2	6
Total realized/unrealized gains (losses) included in AOCI	0	0	0	0
Purchases	83	101	178	124
Sales	(93)	(75)	(107)	(140)
Issuances	(2)	3	(3)	2
Settlements	1	(3)	1	(2)
Transfers into Level 3	13	0	10	0
Transfers out of Level 3	(1)	0	(5)	(2)
Balance, end of period	1,056	925	1,056	925
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0	0	0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0		0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	$ 0	0	$ 0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	$ 0		$ 0