Reinsurance (Related Party Narrative) (Details) - USD ($)		3 Months Ended		6 Months Ended	12 Months Ended
	Apr. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	May 01, 2017	Jan. 01, 2017	Dec. 01, 2016	Nov. 01, 2016	Apr. 01, 2016	Dec. 31, 2014
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability		$ 3,170,000,000			$ 2,234,000,000	$ 3,170,000,000
Other Liabilities		5,445,000,000			4,419,000,000	5,445,000,000
Deferred Policy Acquisition Costs		5,667,000,000			5,015,000,000	5,667,000,000	$ 5,066,000,000						$ 5,097,000,000
Premiums, reinsurance and other receivables		13,853,000,000			12,918,000,000	13,853,000,000
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net		6,339,000,000			5,623,000,000	6,339,000,000	5,777,000,000
Other Assets		689,000,000			547,000,000	689,000,000
Future policy benefits		32,752,000,000			35,715,000,000	32,752,000,000
Policyholder Contract Deposits		36,579,000,000			37,069,000,000	36,579,000,000
Embedded Derivative, Fair Value of Embedded Derivative Asset		360,000,000			175,000,000	360,000,000
Reinsurance recoverables		9,100,000,000			9,100,000,000	9,100,000,000
Income (loss) before provision for income tax					(1,621,000,000)	(4,465,000,000)	1,165,000,000
Deposit Contracts, Assets		1,500,000,000			1,400,000,000	1,500,000,000
Deposit Contracts, Liabilities		1,000,000			198,000,000	1,000,000
Affiliated Entity [Member]
Reinsurance Disclosures [Abstract]
Deposit Contracts, Assets		1,400,000,000			1,300,000,000	1,400,000,000
Deposit Contracts, Liabilities		0			198,000,000	0
Affiliated Entity [Member] | Assumed guaranteed minimum benefits
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability		741,000,000			436,000,000	741,000,000
Net derivatives gains (losses)					177,000,000	(21,000,000)	(47,000,000)
Affiliated Entity [Member] | Ceded guaranteed minimum benefits
Reinsurance Disclosures [Abstract]
Net derivatives gains (losses)					(126,000,000)	46,000,000	$ 54,000,000
Embedded Derivative, Fair Value of Embedded Derivative Asset		171,000,000			2,000,000	171,000,000
Affiliated Entity [Member] | Recapture MLUS [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments												$ 4,300,000,000
Premiums, reinsurance and other receivables												4,000,000,000
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net												$ 87,000,000
Income (loss) before provision for income tax			$ 246,000,000
Affiliated Entity [Member] | Life and Other [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments								$ 214,000,000
Premiums, reinsurance and other receivables								$ 189,000,000
Income (loss) before provision for income tax	$ 17,000,000
Ceded Reinsurance [Member]
Reinsurance Disclosures [Abstract]
Other Liabilities		907,000,000			701,000,000	907,000,000
Premiums, reinsurance and other receivables		12,669,000,000			12,508,000,000	12,669,000,000
Policyholder Contract Deposits		0			0	0
Ceded Reinsurance [Member] | Affiliated Entity [Member]
Reinsurance Disclosures [Abstract]
Other Liabilities		578,000,000			401,000,000	578,000,000
Premiums, reinsurance and other receivables		3,382,000,000			3,254,000,000	3,382,000,000
Policyholder Contract Deposits		0			0	0
Metropolitan Life Insurance Company [Member] | Affiliated Entity [Member] | BHL Recapture GMIB [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments									$ 568,000,000
Premiums, reinsurance and other receivables									140,000,000
Future policy benefits									106,000,000
Policyholder Contract Deposits									460,000,000
Income (loss) before provision for income tax				$ 89,000,000
Brighthouse Life Insurance Company NY [Member] | Affiliated Entity [Member] | Affiliate Recapture Variable Annuities [Member]
Reinsurance Disclosures [Abstract]
Other Liabilities									359,000,000
Cash, Cash Equivalents, and Short-term Investments									150,000,000
Future policy benefits									45,000,000
Policyholder Contract Deposits									168,000,000
New England Life Insurance Company [Member] | Affiliated Entity [Member] | Affiliate Recapture Variable Annuities [Member]
Reinsurance Disclosures [Abstract]
Other Liabilities									68,000,000
Cash, Cash Equivalents, and Short-term Investments									184,000,000
Future policy benefits									34,000,000
Policyholder Contract Deposits									$ 219,000,000
Brighthouse Life Insurance Co of NY [Member] | Affiliated Entity [Member] | SPDARecapture [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments											$ 933,000,000
Deferred Policy Acquisition Costs											23,000,000
Premiums, reinsurance and other receivables											$ 923,000,000
Income (loss) before provision for income tax		22,000,000
Brighthouse Life Insurance Co of NY [Member] | Affiliated Entity [Member] | MRVTermRecapture [Member]
Reinsurance Disclosures [Abstract]
Other Liabilities										$ 158,000,000
Cash, Cash Equivalents, and Short-term Investments										27,000,000
Premiums, reinsurance and other receivables										$ 94,000,000
Income (loss) before provision for income tax		24,000,000
Ceded Credit Risk, Unsecured [Member]
Reinsurance Disclosures [Abstract]
Reinsurance recoverables		2,600,000,000			2,400,000,000	2,600,000,000
Ceded Credit Risk, Unsecured [Member] | Affiliated Entity [Member]
Reinsurance Disclosures [Abstract]
Reinsurance recoverables		$ 2,600,000,000			$ 2,500,000,000	$ 2,600,000,000