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Related Party Transactions (Reinsurance Transactions - Narrative) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Apr. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	May 01, 2017	Jan. 01, 2017
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability		$ 1,682		$ 1,682		$ 2,234
Embedded Derivative, Fair Value of Embedded Derivative Asset		184		184		175
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest		(229)	$ (455)	(253)	$ (1,065)
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net		5,343		5,343		5,623
Premiums, reinsurance and other receivables		13,024		13,024		12,918
Liability for Future Policy Benefits		35,183		35,183		35,715
Policyholder Contract Deposits		37,629		37,629		37,069
Other liabilities relating to variable interest entities		4,589		4,589		4,419
Assumed reinsurance on fixed deferred annuities
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability		321		321		436
Embedded derivatives gains (losses)		50	(7)	117	28
Ceded guaranteed minimum benefits
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Asset		0		0		$ 2
Embedded derivatives gains (losses)					(125)
Affiliated Entity \| Life and Other [Member]
Reinsurance Disclosures [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	$ 17
Cash, Cash Equivalents, and Short-term Investments							$ 214
Premiums, reinsurance and other receivables							$ (189)
Maximum \| Ceded guaranteed minimum benefits
Reinsurance Disclosures [Abstract]
Embedded derivatives gains (losses)		$ (1)	0	$ (1)
Metropolitan Life Insurance Company [Member] \| MLUS Recapture GMIB [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments								$ (568)
Liability for Future Policy Benefits								(106)
Policyholder Contract Deposits								(460)
Metropolitan Life Insurance Company [Member] \| Affiliated Entity \| MLUS Recapture GMIB [Member]
Reinsurance Disclosures [Abstract]
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest			$ 91		$ 89
Premiums, reinsurance and other receivables								140
Brighthouse Life Insurance Company NY [Member] \| Affiliate Recapture Variable Annuities [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments								(150)
Liability for Future Policy Benefits								45
Policyholder Contract Deposits								168
Other liabilities relating to variable interest entities								(359)
New England Life Insurance Company [Member] \| Affiliate Recapture Variable Annuities [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments								184
Liability for Future Policy Benefits								34
Policyholder Contract Deposits								219
Other liabilities relating to variable interest entities								$ (68)