Segment Information (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings (loss)	$ 222	$ 647			$ (555)	$ (327)
Provision for income tax expense (benefit)	25	121			(166)	(119)
Post-tax adjusted earnings (loss)	197	526	$ (586)	$ (734)	(389)	(208)
Less: Net income (loss) attributable to noncontrolling interests	0	0			1	1
Net investment gains (losses)	(62)	(52)			(225)	(213)
Investment Hedge Adjustment	(1,258)	(1,174)			(3,757)	(3,381)
Change in market risk benefits	(610)	1,064			1,185	2,165
Market value adjustments	550	420			1,549	1,282
Net income (loss) attributable to Brighthouse Life Insurance Company	197	526			(390)	(209)
Annuities
Segment Reporting Information [Line Items]
Interest revenue	726	649			2,100	1,871
Interest expense	0	0			0	0
Life
Segment Reporting Information [Line Items]
Interest revenue	100	103			306	299
Interest expense	0	0			0	0
Run-off
Segment Reporting Information [Line Items]
Interest revenue	276	299			906	870
Interest expense	0	0			0	0
Corporate & Other
Segment Reporting Information [Line Items]
Interest revenue	161	148			473	427
Interest expense	17	17			50	53
Operating Segments
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings (loss)	1,003	484			1,204	1,049
Provision for income tax expense (benefit)	189	86			203	169
Post-tax adjusted earnings (loss)	814	398			1,001	880
Less: Net income (loss) attributable to noncontrolling interests	0	0			1	1
Adjusted earnings (loss)	814	398			1,000	879
Operating Segments | Annuities
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings (loss)	396	386			1,170	1,086
Provision for income tax expense (benefit)	75	73			221	204
Post-tax adjusted earnings (loss)	321	313			949	882
Less: Net income (loss) attributable to noncontrolling interests	0	0			0	0
Adjusted earnings (loss)	321	313			949	882
Operating Segments | Life
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings (loss)	47	2			(9)	61
Provision for income tax expense (benefit)	10	(1)			(2)	11
Post-tax adjusted earnings (loss)	37	3			(7)	50
Less: Net income (loss) attributable to noncontrolling interests	0	0			0	0
Adjusted earnings (loss)	37	3			(7)	50
Operating Segments | Run-off
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings (loss)	583	120			114	(35)
Provision for income tax expense (benefit)	121	25			22	(8)
Post-tax adjusted earnings (loss)	462	95			92	(27)
Less: Net income (loss) attributable to noncontrolling interests	0	0			0	0
Adjusted earnings (loss)	462	95			92	(27)
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings (loss)	(23)	(24)			(71)	(63)
Provision for income tax expense (benefit)	(17)	(11)			(38)	(38)
Post-tax adjusted earnings (loss)	(6)	(13)			(33)	(25)
Less: Net income (loss) attributable to noncontrolling interests	0	0			1	1
Adjusted earnings (loss)	(6)	(13)			(34)	(26)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Provision for income tax expense (benefit)	164	(35)			369	288
Net investment gains (losses)	(62)	(52)			(225)	(213)
Net derivative gains (losses), excluding investment hedge adjustments	(98)	(863)			(2,718)	(3,337)
Investment Hedge Adjustment	(5)	(25)			(28)	(86)
Change in market risk benefits	(610)	1,064			1,185	2,165
Market value adjustments	$ (11)	$ 14			$ (1)	$ 9