Dispositions - Separation of Brighthouse (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Aug. 04, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Reduction of long-term debt									$ 944	$ 0	$ 0
Gain (Loss) on Disposition of Other Assets									$ (350)	$ (1,162)	471
Common Stock, Shares, Issued	1,171,824,242				1,168,710,101				1,171,824,242	1,168,710,101
Common Stock, Shares Authorized	3,000,000,000				3,000,000,000				3,000,000,000	3,000,000,000
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent									$ 0	$ (986)	(2,734)
Discontinued Operation, Separation Costs										470	212
Income (loss) from continuing operations before provision for income tax									6,307	3,536	4,281
Policyholder benefits and claims									42,656	38,313	36,358
Other expenses									13,714	13,621	13,749
Income Tax Expense (Benefit)									1,179	(1,470)	693
Income (loss) from discontinued operations, net of income tax	$ 0	$ 0	$ 0	$ 0	$ 0	$ (968)	$ 58	$ (76)	0	(986)	(2,734)
Discontinued Operation, Other fees and costs required										333
Net investment gains (losses)									(298)	(308)	317
Goodwill impairment									0	0	260
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)	0
Policyholder benefits and claims										180	362
Other expenses										(18)	59
Income (loss) from discontinued operations, net of income tax										$ (986)	(2,734)
Common Stock, Shares, Owned by MetLife, INC.			0		22,996,436					22,996,436
Discontinued Operation, Equity Method Investment Retained after Disposal, Ownership Interest after Disposal										19.20%
Equity Method Investment, Quoted Market Value					$ 1,300					$ 1,300
Net investment gains (losses)										(1,016)
Gain (loss) in equity investment value										(95)
Goodwill impairment											260
Goodwill, Impairment Loss, Net of Tax											$ 223
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