Dispositions - 2017 Pending Disposition (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Assets	$ 0	$ 216,983
Disposal Group, Including Discontinued Operation, Liabilities	0	$ 202,707
MetLife Afore [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Gross Profit (Loss)	(98)
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax	(73)
Disposal Group, Including Discontinued Operation, Goodwill	(16)
Disposal Group, Including Discontinued Operation, Assets	3,900
Disposal Group, Including Discontinued Operation, Liabilities	3,700
Disposal Group, Including Discontinued Operation, Separate account assets	3,700
Disposal Group, Including Discontinued Operation, Separate account liabilities	$ 3,700