Reinsurance (Related Party Narrative) (Details) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
	Apr. 30, 2017	Jun. 30, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 01, 2017	Jan. 01, 2017	Dec. 31, 2016
Other invested assets, at estimated fair value			$ 3,224	$ 3,037
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability			4,582	2,516
Other liabilities			4,484	3,455
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents			2,493	3,494	$ 1,363			$ 5,057
Liability for Future Policy Benefit, after Reinsurance			39,081	35,588
Deferred Policy Acquisition Cost			4,327	4,518	5,015			$ 5,667
Premiums, reinsurance and other receivables			14,287	13,113
Deferred Policy Acquisition Costs and Present Value of Future Insurance Profits, Net			4,809	5,086	5,623
Other Assets			464	509
Policyholder account balances			45,121	39,330
Embedded Derivative, Fair Value of Embedded Derivative Asset			217	228
Reinsurance recoverables			13,500	12,300
Income (loss) before provision for income tax			(1,146)	1,121	(1,621)
Deposit Contracts, Assets			2,000	1,400
Deposit Contracts, Liabilities			2,400	1,400
Affiliated Entity
Reinsurance Disclosures [Abstract]
Deposit Contracts, Assets			0	0
Deposit Contracts, Liabilities			164	174
Affiliated Entity | Assumed guaranteed minimum benefits
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability				0
Net derivatives gains (losses)					110
Affiliated Entity | Ceded Guaranteed Minimum Benefit [Member]
Reinsurance Disclosures [Abstract]
Net derivatives gains (losses)				1	(126)
Ceded Reinsurance [Member]
Reinsurance Disclosures [Abstract]
Other liabilities			1,063	655
Premiums, reinsurance and other receivables			13,828	12,669
Policyholder account balances			0	0
Ceded Reinsurance [Member] | Affiliated Entity
Reinsurance Disclosures [Abstract]
Premiums, reinsurance and other receivables			0	0
Policyholder account balances			0	0
Metropolitan Life Insurance Company [Member] | Affiliated Entity | Life and Other [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments						$ 214
Premiums, reinsurance and other receivables						$ (189)
Income (loss) before provision for income tax	$ 17
Metropolitan Life Insurance Company [Member] | Affiliated Entity | BHL Recapture GMIB [Member]
Reinsurance Disclosures [Abstract]
Cash, Cash Equivalents, and Short-term Investments							$ (568)
Liability for Future Policy Benefit, after Reinsurance							(106)
Premiums, reinsurance and other receivables							140
Policyholder account balances							(460)
Income (loss) before provision for income tax		$ 89
Brighthouse Life Insurance Company NY [Member] | Affiliated Entity | Affiliate Recapture Variable Annuities [Member]
Reinsurance Disclosures [Abstract]
Other liabilities							(359)
Cash, Cash Equivalents, and Short-term Investments							150
Future policy benefits							45
Policyholder account balances							168
New England Life Insurance Company [Member] | Affiliated Entity | Assumed guaranteed minimum benefits
Reinsurance Disclosures [Abstract]
Embedded Derivative, Fair Value of Embedded Derivative Liability			443	386
Net derivatives gains (losses)			(53)	53	$ 67
New England Life Insurance Company [Member] | Affiliated Entity | Affiliate Recapture Variable Annuities [Member]
Reinsurance Disclosures [Abstract]
Other liabilities							(68)
Cash, Cash Equivalents, and Short-term Investments							184
Future policy benefits							34
Policyholder account balances							$ 219
Ceded Credit Risk, Unsecured [Member]
Reinsurance Disclosures [Abstract]
Reinsurance recoverables			$ 5,400	5,000
Ceded Credit Risk, Unsecured [Member] | Affiliated Entity
Reinsurance Disclosures [Abstract]
Reinsurance recoverables				$ 0