Impact of New Accounting Standard (Income Statement) (Details) - USD ($) $ 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
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net premiums									$ 15,085.0	$ 13,078.0	$ 12,513.0
Net investment income									3,591.0	3,161.0	3,138.0
Investment related gains (losses), net									(481.0)	(539.0)	567.0
Other revenues									372.0	527.0	449.0
Revenues	$ 5,007.0	$ 5,153.0	$ 4,156.0	$ 4,251.0	$ 4,357.0	$ 4,050.0	$ 3,903.0	$ 3,917.0	18,567.0	16,227.0	16,667.0
Claims and other policy benefits									13,872.0	11,982.0	11,673.0
Liability for Future Policy Benefit, Remeasurement Gain (Loss)									(62.0)	291.0	567.0
Market Risk Benefit, Change in Fair Value, Gain (Loss)									(10.0)	10.0	(58.0)
Interest credited									864.0	682.0	700.0
Other operating expenses									1,089.0	1,009.0	936.0
Interest expense									257.0	191.0	139.0
Total benefits and expenses	4,843.0	4,773.0	3,891.0	3,900.0	3,976.0	4,127.0	3,756.0	3,650.0	17,407.0	15,509.0	15,282.0
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest	164.0	380.0	265.0	351.0	381.0	(77.0)	147.0	267.0	1,160.0	718.0	1,385.0
Provision for income taxes									251.0	197.0	215.0
Net Income	$ 160.0	$ 289.0	$ 207.0	253.0	$ 293.0	$ (75.0)	$ 106.0	197.0	909.0	521.0	1,170.0
Net income attributable to noncontrolling interest									7.0	4.0	0.0
Net Income (Loss) Attributable to Parent									$ 902.0	517.0	1,170.0
Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net premiums				13,078.0				12,513.0
Net investment income				3,161.0				3,138.0
Investment related gains (losses), net				(539.0)				567.0
Other revenues				527.0				449.0
Revenues				16,227.0				16,667.0
Claims and other policy benefits				11,982.0				11,673.0
Liability for Future Policy Benefit, Remeasurement Gain (Loss)				291.0				567.0
Market Risk Benefit, Change in Fair Value, Gain (Loss)				10.0				(58.0)
Interest credited				682.0				700.0
Deferred Policy Acquisition Costs, Amortization Expense				1,344.0				1,325.0
Other operating expenses				1,009.0				936.0
Interest expense				184.0				127.0
Collateral Financing Expense				7.0				12.0
Total benefits and expenses				15,509.0				15,282.0
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest				718.0				1,385.0
Provision for income taxes				197.0				215.0
Net Income				521.0				1,170.0		521.0	1,170.0
Net income attributable to noncontrolling interest				4.0				0.0
Net Income (Loss) Attributable to Parent				517.0				1,170.0
Previously Reported | Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net premiums				13,078.0				12,513.0
Net investment income				3,161.0				3,138.0
Investment related gains (losses), net				(506.0)				560.0
Other revenues				525.0				447.0
Revenues				16,258.0				16,658.0
Claims and other policy benefits				12,046.0				12,776.0
Liability for Future Policy Benefit, Remeasurement Gain (Loss)				0.0				0.0
Market Risk Benefit, Change in Fair Value, Gain (Loss)				0.0				0.0
Interest credited				682.0				700.0
Deferred Policy Acquisition Costs, Amortization Expense				1,499.0				1,416.0
Other operating expenses				1,009.0				936.0
Interest expense				184.0				127.0
Collateral Financing Expense				7.0				12.0
Total benefits and expenses				15,427.0				15,967.0
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest				831.0				691.0
Provision for income taxes				204.0				74.0
Net Income				627.0				617.0		$ 627.0	$ 617.0
Net income attributable to noncontrolling interest				4.0				0.0
Net Income (Loss) Attributable to Parent				623.0				617.0
Revision of Prior Period, Change in Accounting Principle, Adjustment | Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net premiums				0.0				0.0
Net investment income				0.0				0.0
Investment related gains (losses), net				(33.0)				7.0
Other revenues				2.0				2.0
Revenues				(31.0)				9.0
Claims and other policy benefits				(64.0)				(1,103.0)
Liability for Future Policy Benefit, Remeasurement Gain (Loss)				291.0				567.0
Market Risk Benefit, Change in Fair Value, Gain (Loss)				10.0				(58.0)
Interest credited				0.0				0.0
Deferred Policy Acquisition Costs, Amortization Expense				(155.0)				(91.0)
Other operating expenses				0.0				0.0
Interest expense				0.0				0.0
Collateral Financing Expense				0.0				0.0
Total benefits and expenses				82.0				(685.0)
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Extraordinary Items, Noncontrolling Interest				(113.0)				694.0
Provision for income taxes				(7.0)				141.0
Net Income				(106.0)				553.0
Net income attributable to noncontrolling interest				0.0				0.0
Net Income (Loss) Attributable to Parent				$ (106.0)				$ 553.0