Segment Information - Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Operating revenues	$ 4,283	$ 4,167
Revenue adjustments from annuity and life insurance product features	371	170
Credit loss-related adjustments	(20)	(28)
Investment gains (losses)	(6)	37
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans	251	(177)
GLB rider fees ceded to LNBAR	(236)	(232)
Gains (losses) on other non-financial assets	(2)
Total revenues	4,641	3,937
Other Operations
Segment Reporting Information [Line Items]
Operating revenues	60	42
Revenue adjustments from annuity and life insurance product features	0	0
Credit loss-related adjustments	(14)	(8)
Investment gains (losses)	15	15
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans	6	(12)
GLB rider fees ceded to LNBAR	0	0
Gains (losses) on other non-financial assets	(2)
Total revenues	65	37
Annuities | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,156	1,118
Revenue adjustments from annuity and life insurance product features	347	152
Credit loss-related adjustments	(4)	(17)
Investment gains (losses)	(4)	(2)
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans	131	(93)
GLB rider fees ceded to LNBAR	(236)	(232)
Gains (losses) on other non-financial assets	0
Total revenues	1,390	926
Life Insurance | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,231	1,211
Revenue adjustments from annuity and life insurance product features	24	18
Credit loss-related adjustments	(1)	1
Investment gains (losses)	(16)	26
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans	67	(36)
GLB rider fees ceded to LNBAR	0	0
Gains (losses) on other non-financial assets	0
Total revenues	1,305	1,220
Group Protection | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	1,493	1,472
Revenue adjustments from annuity and life insurance product features	0	0
Credit loss-related adjustments	1	(2)
Investment gains (losses)	0	0
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans	47	(36)
GLB rider fees ceded to LNBAR	0
Gains (losses) on other non-financial assets	0
Total revenues	1,541	1,434
Retirement Plan Services | Operating Segments
Segment Reporting Information [Line Items]
Operating revenues	343	324
Revenue adjustments from annuity and life insurance product features	0	0
Credit loss-related adjustments	(2)	(2)
Investment gains (losses)	(1)	(2)
Changes in the fair value of reinsurance-related embedded derivatives, trading securities and certain mortgage loans	0	0
GLB rider fees ceded to LNBAR	0	0
Gains (losses) on other non-financial assets	0
Total revenues	$ 340	$ 320