PENSION AND OTHER POSTRETIREMENT BENEFIT PLANS - Estimated Amortization from Cumulative Other Comprehensive Loss (Details) $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 227
Prior service cost (credit)	(4)
Net effect cost	223
Pension
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	219
Prior service cost (credit)	4
Net effect cost	223
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	8
Prior service cost (credit)	(8)
Net effect cost	$ 0

Amount included in accumulated other comprehensive income (AOCI) expected to be recognized as components of net periodic benefit cost for the fiscal year that follows the most recent annual statement of financial position, including gain (loss), prior service cost (credit), and transition asset (obligation).

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration