Segment Information (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	$ 647	$ 432			$ (327)	$ 4,570
Provision for income tax expense (benefit)	121	78			(119)	909
Post-tax adjusted earnings	526	354	$ (734)	$ 3,307	(208)	3,661	$ 3,711	$ 1,763
Less: Net income (loss) attributable to noncontrolling interests	0	0			1	1
Net investment gains (losses)	(52)	(40)			(213)	(171)
Net derivative gains (losses)	(838)	(590)			(3,251)	1,329	(585)	(3,986)
Investment Hedge Adjustment	(1,174)	(857)			(3,381)	(3,036)
Change in market risk benefits	1,064	982			2,165	2,625	$ (4,105)	$ (4,142)
Market value adjustments	420	399			1,282	918
Net income (loss) attributable to Brighthouse Life Insurance Company	526	354			(209)	3,660
Annuities
Segment Reporting Information [Line Items]
Interest revenue	649	545			1,871	1,642
Interest expense	0	0			0	0
Life
Segment Reporting Information [Line Items]
Interest revenue	103	67			299	316
Interest expense	0	0			0	0
Run-off
Segment Reporting Information [Line Items]
Interest revenue	299	168			870	919
Interest expense	0	0			0	0
Corporate & Other
Segment Reporting Information [Line Items]
Interest revenue	148	100			427	197
Interest expense	17	18			53	51
Operating Segments
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	484	83			1,049	736
Provision for income tax expense (benefit)	86	5			169	104
Post-tax adjusted earnings	398	78			880	632
Less: Net income (loss) attributable to noncontrolling interests	0	0			1	1
Adjusted earnings	398	78			879	631
Operating Segments | Annuities
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	386	243			1,086	1,057
Provision for income tax expense (benefit)	73	43			204	198
Post-tax adjusted earnings	313	200			882	859
Less: Net income (loss) attributable to noncontrolling interests	0	0			0	0
Adjusted earnings	313	200			882	859
Operating Segments | Life
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	2	(91)			61	21
Provision for income tax expense (benefit)	(1)	(19)			11	4
Post-tax adjusted earnings	3	(72)			50	17
Less: Net income (loss) attributable to noncontrolling interests	0	0			0	0
Adjusted earnings	3	(72)			50	17
Operating Segments | Run-off
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	120	(19)			(35)	(188)
Provision for income tax expense (benefit)	25	(4)			(8)	(40)
Post-tax adjusted earnings	95	(15)			(27)	(148)
Less: Net income (loss) attributable to noncontrolling interests	0	0			0	0
Adjusted earnings	95	(15)			(27)	(148)
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(24)	(50)			(63)	(154)
Provision for income tax expense (benefit)	(11)	(15)			(38)	(58)
Post-tax adjusted earnings	(13)	(35)			(25)	(96)
Less: Net income (loss) attributable to noncontrolling interests	0	0			1	1
Adjusted earnings	(13)	(35)			(26)	(97)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Provision for income tax expense (benefit)	(35)	(73)			288	(805)
Net investment gains (losses)	(52)	(40)			(213)	(171)
Net derivative gains (losses)	(863)	(613)			(3,337)	1,291
Investment Hedge Adjustment	(25)	(23)			(86)	(38)
Change in market risk benefits	1,064	982			2,165	2,625
Market value adjustments	$ 14	$ 20			$ 9	$ 89