Fair Value of Financial Instruments - Carrying Amounts of Assets and Liabilities at Estimated Fair Value Measured on a Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Assets
Fixed maturity securities, available for sale	$ 29,511	$ 27,587
Derivative investments	692	548
Total financial assets at fair value	4,400	3,267
Level 1
Assets
Cash and cash equivalents	3,471	2,719
Derivative investments	1	0
Short term investments	115	769
Total financial assets at fair value	6,671	5,311
Liabilities
Fair value of future policy benefits		0
Derivatives:
Total financial liabilities at fair value	0	0
Level 2
Assets
Cash and cash equivalents	0	0
Derivative investments	691	548
Short term investments	17	0
Total financial assets at fair value	25,819	25,431
Liabilities
Fair value of future policy benefits		0
Derivatives:
Total financial liabilities at fair value	107	101
Level 3
Assets
Cash and cash equivalents	0	0
Derivative investments	0	0
Short term investments	303	0
Total financial assets at fair value	4,400	3,267
Liabilities
Fair value of future policy benefits		5
Derivatives:
Total financial liabilities at fair value	3,759	3,409
Fair Value
Assets
Cash and cash equivalents	3,471	2,719
Derivative investments	692	548
Short term investments	435	769
Total financial assets at fair value	36,890	34,009
Liabilities
Fair value of future policy benefits		5
Derivatives:
Total financial liabilities at fair value	3,866	3,510
Carrying Value
Assets
Cash and cash equivalents	3,471	2,719
Derivative investments	692	548
Short term investments	435	769
Total financial assets at fair value	36,890	34,009
Liabilities
Fair value of future policy benefits		5
Derivatives:
Total financial liabilities at fair value	3,866	3,510
FIA embedded derivatives, included in contractholder funds \| Level 1
Derivatives:
Derivative liability	0	0
FIA embedded derivatives, included in contractholder funds \| Level 2
Derivatives:
Derivative liability	0	0
FIA embedded derivatives, included in contractholder funds \| Level 3
Derivatives:
Derivative liability	3,759	3,404
FIA embedded derivatives, included in contractholder funds \| Fair Value
Derivatives:
Derivative liability	3,759	3,404
FIA embedded derivatives, included in contractholder funds \| Carrying Value
Derivatives:
Derivative liability	3,759	3,404
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities \| Level 1
Derivatives:
Derivative liability	0	0
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities \| Level 2
Derivatives:
Derivative liability	107	101
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities \| Level 3
Derivatives:
Derivative liability	0	0
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities \| Fair Value
Derivatives:
Derivative liability	107	101
Reinsurance related embedded derivatives, included in accounts payable and accrued liabilities \| Carrying Value
Derivatives:
Derivative liability	107	101
Asset-backed securities
Assets
Fixed maturity securities, available for sale	7,404	6,266
Asset-backed securities \| Level 1
Assets
Fixed maturity securities, available for sale	0	0
Asset-backed securities \| Level 2
Assets
Fixed maturity securities, available for sale	5,095	4,916
Asset-backed securities \| Level 3
Assets
Fixed maturity securities, available for sale	2,309	1,350
Asset-backed securities \| Fair Value
Assets
Fixed maturity securities, available for sale	7,404	6,266
Asset-backed securities \| Carrying Value
Assets
Fixed maturity securities, available for sale	7,404	6,266
Commercial mortgage-backed securities
Assets
Fixed maturity securities, available for sale	2,946	2,829
Commercial mortgage-backed securities \| Level 1
Assets
Fixed maturity securities, available for sale	0	0
Commercial mortgage-backed securities \| Level 2
Assets
Fixed maturity securities, available for sale	2,921	2,803
Commercial mortgage-backed securities \| Level 3
Assets
Fixed maturity securities, available for sale	25	26
Commercial mortgage-backed securities \| Fair Value
Assets
Fixed maturity securities, available for sale	2,946	2,829
Commercial mortgage-backed securities \| Carrying Value
Assets
Fixed maturity securities, available for sale	2,946	2,829
Corporates
Assets
Fixed maturity securities, available for sale	14,691	14,735
Corporates \| Level 1
Assets
Fixed maturity securities, available for sale	37	25
Corporates \| Level 2
Assets
Fixed maturity securities, available for sale	13,453	13,421
Corporates \| Level 3
Assets
Fixed maturity securities, available for sale	1,201	1,289
Corporates \| Fair Value
Assets
Fixed maturity securities, available for sale	14,691	14,735
Corporates \| Carrying Value
Assets
Fixed maturity securities, available for sale	14,691	14,735
Hybrids
Assets
Fixed maturity securities, available for sale	964	994
Hybrids \| Level 1
Assets
Fixed maturity securities, available for sale	150	175
Hybrids \| Level 2
Assets
Fixed maturity securities, available for sale	814	815
Hybrids \| Level 3
Assets
Fixed maturity securities, available for sale	0	4
Hybrids \| Fair Value
Assets
Fixed maturity securities, available for sale	964	994
Hybrids \| Carrying Value
Assets
Fixed maturity securities, available for sale	964	994
Municipals \| Level 1
Assets
Fixed maturity securities, available for sale	0	0
Municipals \| Level 2
Assets
Fixed maturity securities, available for sale	1,403	1,360
Municipals \| Level 3
Assets
Fixed maturity securities, available for sale	43	43
Municipals \| Fair Value
Assets
Fixed maturity securities, available for sale	1,446	1,403
Municipals \| Carrying Value
Assets
Fixed maturity securities, available for sale	1,446	1,403
Residential mortgage-backed securities
Assets
Fixed maturity securities, available for sale	801	825
Residential mortgage-backed securities \| Level 1
Assets
Fixed maturity securities, available for sale	0	0
Residential mortgage-backed securities \| Level 2
Assets
Fixed maturity securities, available for sale	358	342
Residential mortgage-backed securities \| Level 3
Assets
Fixed maturity securities, available for sale	443	483
Residential mortgage-backed securities \| Fair Value
Assets
Fixed maturity securities, available for sale	801	825
Residential mortgage-backed securities \| Carrying Value
Assets
Fixed maturity securities, available for sale	801	825
U.S. Government
Assets
Fixed maturity securities, available for sale	1,059	342
U.S. Government \| Level 1
Assets
Fixed maturity securities, available for sale	1,059	342
U.S. Government \| Level 2
Assets
Fixed maturity securities, available for sale	0	0
U.S. Government \| Level 3
Assets
Fixed maturity securities, available for sale	0	0
U.S. Government \| Fair Value
Assets
Fixed maturity securities, available for sale	1,059	342
U.S. Government \| Carrying Value
Assets
Fixed maturity securities, available for sale	1,059	342
Foreign Governments
Assets
Fixed maturity securities, available for sale	200	193
Foreign Governments \| Level 1
Assets
Fixed maturity securities, available for sale	0	0
Foreign Governments \| Level 2
Assets
Fixed maturity securities, available for sale	183	176
Foreign Governments \| Level 3
Assets
Fixed maturity securities, available for sale	17	17
Foreign Governments \| Fair Value
Assets
Fixed maturity securities, available for sale	200	193
Foreign Governments \| Carrying Value
Assets
Fixed maturity securities, available for sale	200	193
Equity securities \| Level 1
Assets
Equity securities	1,382	791
Equity securities \| Level 2
Assets
Equity securities	0	0
Equity securities \| Level 3
Assets
Equity securities	8	5
Equity securities \| Fair Value
Assets
Equity securities	1,390	796
Equity securities \| Carrying Value
Assets
Equity securities	1,390	796
Preferred securities
Assets
Equity securities	1,198	1,341
Preferred securities \| Level 1
Assets
Equity securities	456	490
Preferred securities \| Level 2
Assets
Equity securities	740	851
Preferred securities \| Level 3
Assets
Equity securities	2	0
Preferred securities \| Fair Value
Assets
Equity securities	1,198	1,341
Preferred securities \| Carrying Value
Assets
Equity securities	1,198	1,341
Subscription agreements \| Level 1
Assets
Equity securities		0
Subscription agreements \| Level 2
Assets
Equity securities		199
Subscription agreements \| Level 3
Assets
Equity securities		0
Subscription agreements \| Fair Value
Assets
Equity securities		199
Subscription agreements \| Carrying Value
Assets
Equity securities		199
Other long-term investments \| Level 1
Assets
Other long-term investments	0	0
Other long-term investments \| Level 2
Assets
Other long-term investments	144	0
Other long-term investments \| Level 3
Assets
Other long-term investments	49	50
Other long-term investments \| Fair Value
Assets
Other long-term investments	193	50
Other long-term investments \| Carrying Value
Assets
Other long-term investments	$ 193	$ 50

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Short-term Investments, Fair Value

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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