Dispositions - Separation of Brighthouse (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Aug. 04, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduction of long-term debt		$ 0	$ 944	$ 0
Gain (Loss) on Disposition of Other Assets		$ (195)	$ (350)	(1,162)
Common Stock, Shares, Issued		1,177,680,299	1,171,824,242
Common Stock, Shares Authorized		3,000,000,000	3,000,000,000
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent		$ 0	$ 0	(986)
Discontinued Operation, Separation Costs				470
Income (loss) from continuing operations before provision for income tax		6,795	6,307	3,536
Policyholder benefits and claims		41,461	42,656	38,313
Other expenses		13,689	13,714	13,621
Income Tax Expense (Benefit)		886	1,179	(1,470)
Income (loss) from discontinued operations, net of income tax		0	0	(986)
Discontinued Operation, Other fees and costs required				333
Net investment gains (losses)		$ 444	(298)	(308)
Brighthouse Financial, Inc
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduction of long-term debt	$ 944
Gain (Loss) on Disposition of Other Assets				1,016
Income (loss) on disposal of discontinued operations, net of income tax				(1,171)
Policyholder benefits and claims				180
Other expenses				(18)
Income (loss) from discontinued operations, net of income tax				(986)
Common Stock, Shares, Owned by MetLife, INC.	0
Net investment gains (losses)				(1,016)
Gain (loss) in equity investment value				(95)
Impact of Separation
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) on disposal of discontinued operations, net of income tax				(1,302)
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation				42
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent				(1,016)
Realized intercompany gains upon Separation				61
Discontinued Operation, Tax separation agreement Expense				1,093
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal				1,051
Discontinued Operation, Separation Costs				306
Income (loss) from continuing operations before provision for income tax				(131)
Realized Investment Gains (Losses)				(693)
Policyholder benefits and claims				147
Other expenses				218
Income Tax Expense (Benefit)				(927)
Income (loss) from discontinued operations, net of income tax				(1,171)
Impact of Separation | Brighthouse Financial, Inc
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Common Stock, Shares, Issued					96,776,670
Common Stock, Shares Authorized					119,773,106
BHF Common Stock					80.80%
FVO Common Stock | Brighthouse Financial, Inc
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Disposition of Other Assets	$ (327)		$ (327)	$ 95