PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS PENSION PLANS AND OTHER POSTRETIREMENT BENEFITS (Estimated Pretax Amortization of Net Gain (Loss) and Prior Service Credit) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Defined Benefit Pension Plan [Member]
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year	$ 95
Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year	(1)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year	$ (9)