Segment Information (Operating Results) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	$ (1,146)	$ 1,121	$ (1,621)
Provision for income tax expense (benefit)	(338)	153	(738)
Post-tax adjusted earnings	(808)	968	(883)
Less: Net income (loss) attributable to noncontrolling interests	1	1	0
Net investment gains (losses)	92	(204)	(27)
Net derivative gains (losses)	(2,046)	745	(1,468)
Other adjustments to net income (loss)	266	287	336
Net income (loss) attributable to Brighthouse Life Insurance Company	(809)	967	(883)
Annuities
Segment Reporting Information [Line Items]
Interest revenue	1,798	1,523	1,263
Interest expense	0	0	0
Life
Segment Reporting Information [Line Items]
Interest revenue	376	373	300
Interest expense	0	0	(4)
Run-off
Segment Reporting Information [Line Items]
Interest revenue	1,265	1,309	1,399
Interest expense	0	0	23
Corporate & Other
Segment Reporting Information [Line Items]
Interest revenue	53	44	142
Interest expense	60	6	39
Operating Segments
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	658	1,103	582
Provision for income tax expense (benefit)	41	157	459
Post-tax adjusted earnings	617	946	123
Less: Net income (loss) attributable to noncontrolling interests	1	1	0
Adjusted earnings	616	945	123
Operating Segments | Annuities
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	1,233	1,179	1,230
Provision for income tax expense (benefit)	230	201	323
Post-tax adjusted earnings	1,003	978	907
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
Adjusted earnings	1,003	978	907
Operating Segments | Life
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	239	211	(68)
Provision for income tax expense (benefit)	49	43	(30)
Post-tax adjusted earnings	190	168	(38)
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
Adjusted earnings	190	168	(38)
Operating Segments | Run-off
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(580)	(58)	(466)
Provision for income tax expense (benefit)	(126)	(14)	(172)
Post-tax adjusted earnings	(454)	(44)	(294)
Less: Net income (loss) attributable to noncontrolling interests	0	0	0
Adjusted earnings	(454)	(44)	(294)
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(234)	(229)	(114)
Provision for income tax expense (benefit)	(112)	(73)	338
Post-tax adjusted earnings	(122)	(156)	(452)
Less: Net income (loss) attributable to noncontrolling interests	1	1	0
Adjusted earnings	(123)	(157)	(452)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Provision for income tax expense (benefit)	379	4	1,197
Net investment gains (losses)	92	(204)	(27)
Net derivative gains (losses)	(2,046)	745	(1,468)
Other adjustments to net income (loss)	$ 150	$ (523)	$ (708)