Disposition - Hong Kong Sale (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Business	$ 150	$ 4,401	$ 1,746	$ 1,385	$ 4,551	$ 3,131
Net investment gains (losses)	231		61		(57)	76
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal	47		551		1,289	910
MetLife Hong Kong [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (Loss) on Sale of Business			(140)		11	(140)
Net investment gains (losses)			(100)			(100)
Goodwill, Written off Related to Sale of Business Unit			71			71
Discontinued Operation, Tax (Expense) Benefit from Provision for (Gain) Loss on Disposal			$ (40)			$ (40)
Disposal Group, Including Discontinued Operation, Assets							$ 2,900
Total Loss on Sale of Business	$ 129				$ 129