Segment Information (Operating Results) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	$ (2,549)		$ 439		$ 3,555	$ (536)
Provision for income tax expense (benefit)	(552)		76		713	(145)
Post-tax adjusted earnings	(1,997)	$ 4,839	363	$ (754)	2,842	(391)
Less: Net income (loss) attributable to noncontrolling interests	1		1		1	1
Net investment gains (losses)	(33)		56		(52)	46
Net derivative gains (losses)	(2,650)		108		4,097	(1,202)
Other adjustments to net income (loss)	67		69		151	131
Net income (loss) attributable to Brighthouse Life Insurance Company	(1,998)		362		2,841	(392)
Annuities
Segment Reporting Information [Line Items]
Interest revenue	402		468		860	886
Interest expense	0		0		0	0
Life
Segment Reporting Information [Line Items]
Interest revenue	57		101		157	183
Interest expense	0		0		0	0
Run-off
Segment Reporting Information [Line Items]
Interest revenue	166		339		490	615
Interest expense	0		0		0	0
Corporate & Other
Segment Reporting Information [Line Items]
Interest revenue	15		10		31	22
Interest expense	17		16		34	26
Operating Segments
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(6)		321		226	581
Provision for income tax expense (benefit)	(18)		52		14	90
Post-tax adjusted earnings	12		269		212	491
Less: Net income (loss) attributable to noncontrolling interests	1		1		1	1
Adjusted earnings	11		268		211	490
Operating Segments | Annuities
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	193		321		576	668
Provision for income tax expense (benefit)	32		59		104	122
Post-tax adjusted earnings	161		262		472	546
Less: Net income (loss) attributable to noncontrolling interests	0		0		0	0
Adjusted earnings	161		262		472	546
Operating Segments | Life
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	46		72		67	97
Provision for income tax expense (benefit)	10		15		14	20
Post-tax adjusted earnings	36		57		53	77
Less: Net income (loss) attributable to noncontrolling interests	0		0		0	0
Adjusted earnings	36		57		53	77
Operating Segments | Run-off
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(147)		2		(236)	(44)
Provision for income tax expense (benefit)	(32)		0		(51)	(10)
Post-tax adjusted earnings	(115)		2		(185)	(34)
Less: Net income (loss) attributable to noncontrolling interests	0		0		0	0
Adjusted earnings	(115)		2		(185)	(34)
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Pre-tax adjusted earnings	(98)		(74)		(181)	(140)
Provision for income tax expense (benefit)	(28)		(22)		(53)	(42)
Post-tax adjusted earnings	(70)		(52)		(128)	(98)
Less: Net income (loss) attributable to noncontrolling interests	1		1		1	1
Adjusted earnings	(71)		(53)		(129)	(99)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Provision for income tax expense (benefit)	534		(24)		(699)	235
Net investment gains (losses)	(33)		56		(52)	46
Net derivative gains (losses)	(2,650)		108		4,097	(1,202)
Other adjustments to net income (loss)	$ 140		$ (46)		$ (716)	$ 39