Fair Value (Unobservable Input Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Residential mortgage loans - FVO
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 165	$ 188
Total realized/unrealized gains (losses) included in net income (loss)	(2)	2
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	0	0
Sales	(9)	(5)
Issuances	0	0
Settlements	(5)	(5)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	149	180
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(5)	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
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	(162)	40
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(538)	1,122
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	594	(146)
Total realized/unrealized gains (losses) included in net income (loss)	(251)	71
Total realized/unrealized gains (losses) included in AOCI	(604)	1,200
Purchases	0	(10)
Sales	0	0
Issuances	0	0
Settlements	96	(76)
Transfers into Level 3	1	0
Transfers out of Level 3	2	0
Balance, end of period	(162)	1,039
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(162)	40
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(538)	1,122
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	671	(1,422)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	21	(4)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Balance, beginning of period	(1,141)	(742)
Total realized/unrealized gains (losses) included in net income (loss)	673	(1,422)
Total realized/unrealized gains (losses) included in AOCI	21	(4)
Purchases	0	0
Sales	0	0
Issuances	0	0
Settlements	(61)	(64)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	(508)	(2,232)
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	671	(1,422)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	21	(4)
Corporate fixed maturity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	24,101	14,229
Total realized/unrealized gains (losses) included in net income (loss)	(1)	(60)
Total realized/unrealized gains (losses) included in AOCI	(1,182)	(1,200)
Purchases	1,012	2,392
Sales	(274)	(565)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	235	5,503
Transfers out of Level 3	(472)	(490)
Balance, end of period	23,419	19,809
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	(4)	(59)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(1,175)	(1,201)
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	(4)	(59)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(1,175)	(1,201)
Foreign government
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	117	117
Total realized/unrealized gains (losses) included in net income (loss)	0	(2)
Total realized/unrealized gains (losses) included in AOCI	0	(7)
Purchases	23	32
Sales	(3)	(3)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	7	28
Transfers out of Level 3	(12)	(61)
Balance, end of period	132	104
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	(2)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0	(7)
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	(2)
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	0	(7)
Structured Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	5,289	4,458
Total realized/unrealized gains (losses) included in net income (loss)	9	10
Total realized/unrealized gains (losses) included in AOCI	(46)	(311)
Purchases	613	372
Sales	(356)	(186)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	13	45
Transfers out of Level 3	(15)	(374)
Balance, end of period	5,507	4,014
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	7	11
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(43)	(312)
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	7	11
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(43)	(312)
Municipals
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	0	7
Total realized/unrealized gains (losses) included in net income (loss)	0	0
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	5	0
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	(7)
Balance, end of period	5	0
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	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
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	150	430
Total realized/unrealized gains (losses) included in net income (loss)	4	(28)
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	4	2
Sales	(4)	(32)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	154	372
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	3	(12)
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	3	(12)
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	701	625
Total realized/unrealized gains (losses) included in net income (loss)	18	(63)
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	10	140
Sales	(12)	(103)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	101	14
Transfers out of Level 3	(6)	(96)
Balance, end of period	812	517
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	19	(65)
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	19	(65)
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	43	32
Total realized/unrealized gains (losses) included in net income (loss)	0	0
Total realized/unrealized gains (losses) included in AOCI	(2)	(1)
Purchases	61	354
Sales	(1)	(8)
Issuances	0	0
Settlements	0	0
Transfers into Level 3	4	5
Transfers out of Level 3	(3)	(14)
Balance, end of period	102	368
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	0	0
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(2)	(1)
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
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	(2)	(1)
Other Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	573	455
Total realized/unrealized gains (losses) included in net income (loss)	13	4
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	70	16
Sales	0	0
Issuances	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	656	475
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	14	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	14	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	1,079	980
Total realized/unrealized gains (losses) included in net income (loss)	(10)	(8)
Total realized/unrealized gains (losses) included in AOCI	0	0
Purchases	79	144
Sales	(13)	(62)
Issuances	(1)	(1)
Settlements	2	0
Transfers into Level 3	0	10
Transfers out of Level 3	(3)	(17)
Balance, end of period	1,133	1,046
Changes in unrealized gains (losses) included in net income (loss) for the instruments still held at end of period	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
Changes in unrealized gains (losses) included in AOCI for the instruments still held at end of period	$ 0	$ 0