Segment Information - Reconciliation of Income (Loss) from Operations by Segment to Consolidated Net Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating revenues		$ 18,342	$ 16,027	$ 17,963
Interest credited		3,443	3,248	2,877
Commissions		2,141	2,075	2,189
General and administrative expenses		2,738	2,543	2,407
Interest and debt expense		336	331	283
Total federal income tax expense (benefit)		747	(396)	367
Reconciliation of total income (loss) from operations to net income (loss):
Net annuity product features, pre-tax		2,508	68	4,133
Net life insurance product features, pre-tax		(207)	(393)	26
Credit loss-related adjustments, pre-tax		(152)	(80)	(130)
Investment gains (losses), pre-tax		(483)	(959)	20
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans, pre-tax		535	(802)	(52)
Gains (losses) on other non-financial assets – sale of subsidiaries/businesses, pre-tax		582
Impairment of intangibles				(634)
Other items, pre-tax		(270)	(55)	(109)
Certain legal accruals, before tax	$ (12)	(129)	(12)	(147)
Severance expense for workforce realignment, before tax		(74)	(7)
Transaction and integration costs for acquisitions or divestiture, before tax		(40)	(34)
Deferred compensation mark-to-market adjustment, before tax		(15)	(2)	38
Income tax benefit (expense) related to the above pre-tax items		(553)	479	(814)
Net income (loss)		3,275	(752)	1,358
Operating Segments and Corporate Non Segment
Segment Reporting Information [Line Items]
Operating revenues		18,342	16,027	17,963
Benefits and policyholder liability remeasurement (gain) loss		7,742	5,945	11,175
Interest credited		3,443	3,248	2,877
Commissions		2,141	2,075	2,189
General and administrative expenses		2,524	2,533	2,298
Interest and debt expense		336	331	283
Other		615	839	671
Total operating expenses		16,801	14,971	19,493
Total federal income tax expense (benefit)		226	66	(448)
Total income (loss) from operations		1,315	990	(1,082)
Other Operations
Segment Reporting Information [Line Items]
Operating revenues		160	(755)	156
Benefits and policyholder liability remeasurement (gain) loss		12	(866)	66
Interest credited		32	36	39
Commissions		0	0	0
General and administrative expenses		256	258	267
Interest and debt expense		336	331	283
Other		(10)	(8)	(5)
Total operating expenses		626	(249)	650
Total federal income tax expense (benefit)		(96)	(112)	(93)
Total income (loss) from operations		(370)	(394)	(401)
Annuities | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues		4,896	3,002	4,482
Benefits and policyholder liability remeasurement (gain) loss		145	(1,504)	253
Interest credited		1,536	1,252	894
Commissions		1,115	971	1,018
General and administrative expenses		495	471	408
Interest and debt expense		0	0	0
Other		217	599	563
Total operating expenses		3,508	1,789	3,136
Total federal income tax expense (benefit)		228	140	185
Total income (loss) from operations		1,160	1,073	1,161
Life Insurance | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues		6,248	6,907	6,747
Benefits and policyholder liability remeasurement (gain) loss		3,893	4,583	6,925
Interest credited		1,194	1,290	1,310
Commissions		461	571	698
General and administrative expenses		563	617	554
Interest and debt expense		0	0	0
Other		242	77	(59)
Total operating expenses		6,353	7,138	9,428
Total federal income tax expense (benefit)		(42)	(72)	(587)
Total income (loss) from operations		(63)	(159)	(2,094)
Group Protection | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues		5,717	5,563	5,304
Benefits and policyholder liability remeasurement (gain) loss		3,692	3,732	3,931
Interest credited		6	5	5
Commissions		462	446	394
General and administrative expenses		870	846	766
Interest and debt expense		0	0	0
Other		149	155	156
Total operating expenses		5,179	5,184	5,252
Total federal income tax expense (benefit)		113	80	11
Total income (loss) from operations		425	299	41
Retirement Plan Services | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues		1,321	1,310	1,274
Benefits and policyholder liability remeasurement (gain) loss		0	0	0
Interest credited		675	665	629
Commissions		103	87	79
General and administrative expenses		340	341	303
Interest and debt expense		0	0	0
Other		17	16	16
Total operating expenses		1,135	1,109	1,027
Total federal income tax expense (benefit)		23	30	36
Total income (loss) from operations		$ 163	$ 171	$ 211