RETIREMENT BENEFITS - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Change in accumulated other comprehensive income (loss)
Beginning of period balance, net of tax	$ (5,176)		$ (5,164)
Actuarial assumptions changes and plan experience	(260)		(508)
Net asset gain due to difference between actual and expected returns	43		296
Net amortization	56		112
Prior service cost	0		(5)
Curtailment/settlement gain	7		7
Foreign exchange impact and other	(64)		(122)
Change in deferred taxes, net	83		73
Change, net of tax	(135)	$ (27)	(147)	$ (492)
End of period balance, net of tax	$ (5,311)		$ (5,311)