The charge against earnings in the period for known or estimated future costs arising from requirements to perform environmental remediation activities.

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Contingencies, Commitments and Guarantees (Contingencies - Narrative) (Details) $ in Thousands				3 Months Ended		12 Months Ended
	May 02, 2017 USD ($)	Nov. 30, 2016 USD ($)	Aug. 31, 2016 USD ($)	Mar. 31, 2017 USD ($) Claims	Mar. 31, 2016 Claims	Dec. 31, 2016 USD ($) Claims
Minimum
Loss Contingencies
Loss Contingency, Range of Possible Loss, Portion Not Accrued				$ 0
Maximum
Loss Contingencies
Loss Contingency, Range of Possible Loss, Portion Not Accrued				$ 400,000
Asbestos Related Claims
Loss Contingencies
Asbestos-Related Claims \| Claims				1,104	1,386	4,146
Superfund Site Settlement Agreements
Loss Contingencies
Number of regulatory matters and other claims \| Claims				2
Maximum estimate of costs for environmental testing				$ 100
Superfund Site Settlement Agreements \| Minimum
Loss Contingencies
Damages Sought				1,000
Superfund Site Settlement Agreements \| Maximum
Loss Contingencies
Maximum estimate of aggregate costs to resolve matter				1,000
Hartshorne V. MetLife Inc., et al. \| Compensatory Damages
Loss Contingencies
Damages Sought				$ 200
Hartshorne V. MetLife Inc., et al. \| Punitive Damages
Loss Contingencies
Damages Sought		$ 7,000	$ 15,000
Hartshorne V. MetLife Inc., et al. \| Attorney's fees and costs \| Subsequent Event [Member]
Loss Contingencies
Damages Sought	$ 6,500
City of Birmingham Retirement and Relief System v. MetLife, Inc., et al. [Member]
Loss Contingencies
Litigation Settlement, Amount						$ 9,750