Separation (New Financing Arrangements - Narrative) (Details) - USD ($) $ in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2017	Aug. 02, 2017	Jul. 21, 2017	Apr. 30, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Secured Debt		$ 1,235	$ 1,235		$ 1,235						$ 4,071
Preferred Stock, Shares Issued		25,500,000	25,500,000		25,500,000						25,500,000
Other General and Administrative Expense			$ 810	$ 516	$ 1,251	$ 989
Spinoff [Member]
Debt Instrument [Line Items]
Preferred Stock, Shares Issued		50,000	50,000		50,000
Preferred Stock, Dividend Payment Rate, Variable		0.065
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 49
Debt Issuance Costs, Gross		25	$ 25		$ 25
Line of Credit Facility, Maximum Borrowing Capacity		536	536		536					$ 3,000
Spinoff [Member] | 2027 Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 1,500	$ 1,500		$ 1,500
Debt Instrument, Maturity Date		Jun. 30, 2027
Debt Instrument, Interest Rate, Stated Percentage		3.70%	3.70%		3.70%
Spinoff [Member] | 2047 Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 1,500	$ 1,500		$ 1,500
Debt Instrument, Maturity Date		Jun. 30, 2047
Debt Instrument, Interest Rate, Stated Percentage		4.70%	4.70%		4.70%
Brighthouse Reinsurance Company of Delaware [Member] | Spinoff [Member]
Debt Instrument [Line Items]
Secured Debt										8,100
Line of Credit Facility, Maximum Borrowing Capacity										$ 10,000
Subsequent Event [Member] | Spinoff [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount								$ 500
Line of Credit Facility, Maximum Borrowing Capacity									$ 600
Other General and Administrative Expense	$ 7
Line of Credit Facility, Current Borrowing Capacity									$ 500
Redemption Price							101.00%