Segment Information - Reconciliation of Income (Loss) from Operations by Segment to Consolidated Net Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Operating revenues	$ 4,197.0	$ (235.0)	$ 8,363.0	$ 3,890.0
Interest credited	849.0	781.0	1,672.0	1,533.0
Interest and debt expense	40.0	48.0	80.0	96.0
Total federal income tax expense (benefit)	131.0	166.0	(21.0)	333.0
Reconciliation of total income (loss) from operations to net income (loss):
Net annuity product features, pre-tax (4)	721.0	414.0	256.0	1,411.0
Net life insurance product features, pre-tax	(57.0)	(14.0)	(36.0)	(146.0)
Credit loss-related adjustments, pre-tax	(25.0)	(33.0)	(53.0)	(33.0)
Investment gains (losses), pre-tax	(81.0)	(204.0)	(44.0)	(260.0)
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans, pre-tax	(55.0)	43.0	(233.0)	90.0
GLB rider fees ceded to LNBAR, pre-tax	(237.0)	(232.0)	(469.0)	(462.0)
Gains (losses) on other non-financial assets -sale of subsidiaries/businesses, pre-tax		481.0		481.0
Other items, pre-tax	1.0	(23.0)	(31.0)	(94.0)
Income tax benefit (expense) related to the above pre-tax items	(57.0)	(114.0)	123.0	(236.0)
Net income (loss)	627.0	761.0	188.0	1,418.0
Changes in non-performance	443.0	167.0	(176.0)	863.0
Severance expense for workforce realignment, before tax	(2.0)	(7.0)	(8.0)	(56.0)
Transaction and integration costs for acquisitions or divestiture, before tax	2.0	(16.0)	(18.0)	(27.0)
Deferred compensation mark-to-market adjustment, before tax	1.0		(5.0)	(8.0)
Certain legal accruals, before tax				(3.0)
Embedded Derivative Instruments
Reconciliation of total income (loss) from operations to net income (loss):
Unrealized Gain (Loss) on Derivatives	112.0	76.0	86.0	218.0
Qualifying Hedges
Reconciliation of total income (loss) from operations to net income (loss):
Unrealized Gain (Loss) on Derivatives	166.0	171.0	346.0	330.0
Operating Segments and Corporate Non Segment
Segment Reporting Information [Line Items]
Operating revenues	4,197.0	(235.0)	8,363.0	3,890.0
Benefits and policyholder liability remeasurement (gain) loss	1,570.0	(2,826.0)	3,315.0	(1,099.0)
Interest credited	849.0	781.0	1,672.0	1,533.0
Commissions	536.0	770.0	1,076.0	1,013.0
General and administrative expenses	602.0	727.0	1,211.0	1,200.0
Interest and debt expense	40.0	48.0	80.0	96.0
Other	110.0	(260.0)	227.0	347.0
Total operating expenses	3,707.0	(760.0)	7,581.0	3,090.0
Total federal income tax expense (benefit)	73.0	82.0	107.0	133.0
Total income (loss) from operations	417.0	443.0	675.0	667.0
Other Operations
Segment Reporting Information [Line Items]
Operating revenues	35.0	34.0	77.0	59.0
Benefits and policyholder liability remeasurement (gain) loss	4.0	1.0	6.0	1.0
Interest credited	13.0	7.0	27.0	16.0
Commissions	0.0	0.0	0.0	0.0
General and administrative expenses	35.0	45.0	83.0	83.0
Interest and debt expense	40.0	48.0	80.0	96.0
Other	0.0	1.0	0.0	1.0
Total operating expenses	92.0	102.0	196.0	197.0
Total federal income tax expense (benefit)	(13.0)	(14.0)	(20.0)	(24.0)
Total income (loss) from operations	(44.0)	(54.0)	(99.0)	(114.0)
Reconciliation of total income (loss) from operations to net income (loss):
Gains (losses) on other non-financial assets -sale of subsidiaries/businesses, pre-tax		481.0		481.0
Annuities | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,130.0	1,141.0	2,249.0	2,319.0
Benefits and policyholder liability remeasurement (gain) loss	30.0	39.0	57.0	66.0
Interest credited	439.0	378.0	859.0	731.0
Commissions	292.0	524.0	590.0	524.0
General and administrative expenses	126.0	235.0	251.0	235.0
Interest and debt expense	0.0	0.0	0.0	0.0
Other	(13.0)	(329.0)	(25.0)	191.0
Total operating expenses	874.0	847.0	1,732.0	1,747.0
Total federal income tax expense (benefit)	34.0	42.0	68.0	97.0
Total income (loss) from operations	222.0	252.0	449.0	475.0
Reconciliation of total income (loss) from operations to net income (loss):
Gains (losses) on other non-financial assets -sale of subsidiaries/businesses, pre-tax		0.0		0.0
Life Insurance | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,218.0	1,318.0	2,429.0	2,498.0
Benefits and policyholder liability remeasurement (gain) loss	626.0	717.0	1,357.0	1,454.0
Interest credited	222.0	227.0	442.0	449.0
Commissions	90.0	107.0	178.0	218.0
General and administrative expenses	131.0	138.0	260.0	279.0
Interest and debt expense	0.0	0.0	0.0	0.0
Other	83.0	36.0	176.0	75.0
Total operating expenses	1,152.0	1,225.0	2,413.0	2,475.0
Total federal income tax expense (benefit)	8.0	14.0	(11.0)	(5.0)
Total income (loss) from operations	58.0	79.0	27.0	28.0
Reconciliation of total income (loss) from operations to net income (loss):
Gains (losses) on other non-financial assets -sale of subsidiaries/businesses, pre-tax		0.0		0.0
Group Protection | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,486.0	(3,051.0)	2,957.0	(1,626.0)
Benefits and policyholder liability remeasurement (gain) loss	910.0	(3,583.0)	1,895.0	(2,620.0)
Interest credited	1.0	1.0	0.0	2.0
Commissions	126.0	113.0	253.0	222.0
General and administrative expenses	227.0	226.0	449.0	435.0
Interest and debt expense	0.0	0.0	0.0	0.0
Other	36.0	28.0	65.0	71.0
Total operating expenses	1,300.0	(3,215.0)	2,662.0	(1,890.0)
Total federal income tax expense (benefit)	39.0	35.0	62.0	55.0
Total income (loss) from operations	147.0	129.0	233.0	209.0
Reconciliation of total income (loss) from operations to net income (loss):
Gains (losses) on other non-financial assets -sale of subsidiaries/businesses, pre-tax		0.0		0.0
Retirement Plan Services | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	328.0	323.0	651.0	640.0
Benefits and policyholder liability remeasurement (gain) loss	0.0	0.0	0.0	0.0
Interest credited	174.0	168.0	344.0	335.0
Commissions	28.0	26.0	55.0	49.0
General and administrative expenses	83.0	83.0	168.0	168.0
Interest and debt expense	0.0	0.0	0.0	0.0
Other	4.0	4.0	11.0	9.0
Total operating expenses	289.0	281.0	578.0	561.0
Total federal income tax expense (benefit)	5.0	5.0	8.0	10.0
Total income (loss) from operations	$ 34.0	37.0	$ 65.0	69.0
Reconciliation of total income (loss) from operations to net income (loss):
Gains (losses) on other non-financial assets -sale of subsidiaries/businesses, pre-tax		$ 0.0		$ 0.0