Basis of Presentation and Significant Accounting Policies Impact of Accounting Changes (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance	$ 484				$ 502				$ 484	$ 502	$ 646	$ 723	$ 638
Accumulated Other Comprehensive Income (Loss), Net of Tax	(2,849)				(3,841)				(2,849)	(3,841)	128	1,105
OCI, Liability for Future Policy Benefit, Gain (Loss), before Reclassification Adjustment and Tax											(33)
Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change											(44)
Deferred income taxes, net	1,173				1,437				1,173	1,437	281	64
Reinsurance Recoverables, Including Reinsurance Premium Paid	7,104				6,964				7,104	6,964	6,524	6,013
Retained Earnings (Accumulated Deficit)	19,007				17,058				19,007	17,058	15,770	13,918
Total stockholders’ equity	15,327				13,676				15,327	13,676	17,805	18,491
Benefits, losses and loss adjustment expenses									14,238	13,138	12,720
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest									3,088	2,262	2,905
Income tax expense									584	443	534
Net income (loss)	771	$ 651	$ 547	$ 535	592	$ 340	$ 444	$ 443	2,504	1,819	2,371
Net income (loss) available to common stockholders	$ 766	$ 645	$ 542	$ 530	$ 587	$ 334	$ 439	$ 438	$ 2,483	$ 1,798	$ 2,350
Earnings Per Share, Basic	$ 2.55	$ 2.12	$ 1.75	$ 1.69	$ 1.85	$ 1.04	$ 1.34	$ 1.32	$ 8.09	$ 5.54	$ 6.73
Net income available to common stockholders	$ 2.51	$ 2.09	$ 1.73	$ 1.66	$ 1.82	$ 1.02	$ 1.32	$ 1.30	$ 7.97	$ 5.46	$ 6.64
Change in net unrealized gain (loss) on fixed maturities, available-for-sale ("AFS")									$ 1,112	$ (4,225)	$ (1,224)
Change in liability for future policy benefits adjustments									(10)	94	27
OCI, net of tax									992	(3,969)	(977)
Comprehensive income (loss)									3,496	(2,150)	1,394
Previously Reported [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance					$ 561					561	596	638
Accumulated Other Comprehensive Income (Loss), Net of Tax					(3,876)					(3,876)	172	1,170
Deferred income taxes, net					1,449					1,449	270	46
Reinsurance Recoverables, Including Reinsurance Premium Paid					6,966					6,966	6,523	6,011
Retained Earnings (Accumulated Deficit)					17,048					17,048	15,764	13,918
Total stockholders’ equity					13,631					13,631	17,843	18,556
Benefits, losses and loss adjustment expenses										13,142	12,729
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										2,258	2,896
Income tax expense										443	531
Net income (loss)										1,815	2,365
Net income (loss) available to common stockholders										$ 1,794	$ 2,344
Earnings Per Share, Basic										$ 5.52	$ 6.71
Net income available to common stockholders										$ 5.44	$ 6.62
Change in net unrealized gain (loss) on fixed maturities, available-for-sale ("AFS")										$ (4,210)	$ (1,218)
Change in liability for future policy benefits adjustments										0	0
OCI, net of tax										(4,048)	(998)
Comprehensive income (loss)										(2,233)	1,367
Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance					(59)					(59)	50	85
Accumulated Other Comprehensive Income (Loss), Net of Tax					35					35	(44)	(65)
Deferred income taxes, net					(12)					(12)	11	18
Reinsurance Recoverables, Including Reinsurance Premium Paid					(2)					(2)	1	2
Retained Earnings (Accumulated Deficit)					10					10	6	0
Total stockholders’ equity					45					45	(38)	(65)
Benefits, losses and loss adjustment expenses										(4)	(9)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest										4	9
Income tax expense										0	3
Net income (loss)										4	6
Net income (loss) available to common stockholders										$ 4	$ 6
Earnings Per Share, Basic										$ 0.02	$ 0.02
Net income available to common stockholders										$ 0.02	$ 0.02
Change in net unrealized gain (loss) on fixed maturities, available-for-sale ("AFS")										$ (15)	$ (6)
Change in liability for future policy benefits adjustments										94	27
OCI, net of tax										79	21
Comprehensive income (loss)										83	27
Fixed Annuity
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance	$ 137				140				137	140	188		189
OCI, Liability for Future Policy Benefit, Gain (Loss), before Reclassification Adjustment and Tax											(11)
Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change											(7)
Life Conversions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance	64				65				64	65	94		94
OCI, Liability for Future Policy Benefit, Gain (Loss), before Reclassification Adjustment and Tax											(7)
Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change											(14)
Paid Up Life
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance	185				192				185	192	262		267
OCI, Liability for Future Policy Benefit, Gain (Loss), before Reclassification Adjustment and Tax											(15)
Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change											(17)
Deferred Profit Liability
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance	20				19				20	19	20		0
OCI, Liability for Future Policy Benefit, Gain (Loss), before Reclassification Adjustment and Tax											0
Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change											2
Long-Duration Insurance, Other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance	$ 78				$ 86				$ 78	$ 86	82		$ 88
OCI, Liability for Future Policy Benefit, Gain (Loss), before Reclassification Adjustment and Tax											0
Liability for Future Policy Benefit, Expected Future Policy Benefit, Increase (Decrease) for Other Change											(8)
Cumulative Effect, Period of Adoption, Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												85
Accumulated Other Comprehensive Income (Loss), Net of Tax												(65)
Deferred income taxes, net												18
Reinsurance Recoverables, Including Reinsurance Premium Paid												2
Cumulative Effect, Period of Adoption, Adjustment [Member] | Removal of shadow reserve [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												(26)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Update cash flow assumptions and establish DPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Effect of measurement at current single-A rate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												111
Cumulative Effect, Period of Adoption, Adjustment [Member] | Fixed Annuity
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												17
Cumulative Effect, Period of Adoption, Adjustment [Member] | Fixed Annuity | Removal of shadow reserve [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												(26)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Fixed Annuity | Update cash flow assumptions and establish DPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												(16)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Fixed Annuity | Effect of measurement at current single-A rate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												59
Cumulative Effect, Period of Adoption, Adjustment [Member] | Life Conversions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												21
Cumulative Effect, Period of Adoption, Adjustment [Member] | Life Conversions | Removal of shadow reserve [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Life Conversions | Update cash flow assumptions and establish DPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Life Conversions | Effect of measurement at current single-A rate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												21
Cumulative Effect, Period of Adoption, Adjustment [Member] | Paid Up Life
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												27
Cumulative Effect, Period of Adoption, Adjustment [Member] | Paid Up Life | Removal of shadow reserve [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Paid Up Life | Update cash flow assumptions and establish DPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												(2)
Cumulative Effect, Period of Adoption, Adjustment [Member] | Paid Up Life | Effect of measurement at current single-A rate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												29
Cumulative Effect, Period of Adoption, Adjustment [Member] | Deferred Profit Liability
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												18
Cumulative Effect, Period of Adoption, Adjustment [Member] | Deferred Profit Liability | Removal of shadow reserve [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Deferred Profit Liability | Update cash flow assumptions and establish DPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												18
Cumulative Effect, Period of Adoption, Adjustment [Member] | Deferred Profit Liability | Effect of measurement at current single-A rate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Long-Duration Insurance, Other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												2
Cumulative Effect, Period of Adoption, Adjustment [Member] | Long-Duration Insurance, Other | Removal of shadow reserve [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Long-Duration Insurance, Other | Update cash flow assumptions and establish DPL [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												0
Cumulative Effect, Period of Adoption, Adjustment [Member] | Long-Duration Insurance, Other | Effect of measurement at current single-A rate [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance												2
Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance											646	723
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Fixed Annuity
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance											188	206
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Life Conversions
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance											94	115
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Paid Up Life
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance											262	294
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Deferred Profit Liability
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance											20	18
Cumulative Effect, Period of Adoption, Adjusted Balance [Member] | Long-Duration Insurance, Other
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, before Reinsurance											$ 82	$ 90