EMPLOYEE BENEFIT PLANS (Future Amortization) (Details) - Regulatory Asset [Member] $ in Millions	12 Months Ended
Dec. 31, 2016 USD ($)
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Loss	$ 7
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Net Loss	$ 0

Amount included in accumulated other comprehensive income (AOCI) related to gain (loss) 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.

No definition available.

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