Goodwill (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2012
Goodwill [Line Items]
Goodwill	$ 9,872	$ 10,542	$ 9,477	$ 9,953
Reduction of accumulated impairment		65
Goodwill Disposition	70	8
MetLife Assurance Limited
Goodwill [Line Items]
Goodwill Disposition	60
Japan
Goodwill [Line Items]
Goodwill	4,400	4,700	4,300
Retail
Goodwill [Line Items]
Goodwill	1,433	1,433	1,433	1,433
Goodwill impairment testing attributed to reportable segments	34
Reduction of accumulated impairment		0
Goodwill Disposition	0	0
Group, Voluntary & Worksite Benefits
Goodwill [Line Items]
Goodwill	138	138	138	138
Goodwill impairment testing attributed to reportable segments	9
Reduction of accumulated impairment		0
Goodwill Disposition	0	0
Corporate Benefit Funding
Goodwill [Line Items]
Goodwill	840	900	840	900
Goodwill impairment testing attributed to reportable segments	186
Reduction of accumulated impairment		0
Goodwill Disposition	60	0
Corporate Benefit Funding | MetLife Assurance Limited
Goodwill [Line Items]
Goodwill Disposition	60
Corporate & Other
Goodwill [Line Items]
Goodwill	229	229	$ 229	$ 229
Reduction of accumulated impairment		65
Goodwill Disposition	$ 0	0
MetLife Bank
Goodwill [Line Items]
Reduction of accumulated impairment		$ 65