SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Summary of Significant Accounting Policies - PPE (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 3,242	$ 3,338
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment	355	286
Net property, plant and equipment	2,887	3,052
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	8	8
Construction Work-In-Process [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	54	37
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	341	340
Pipelines [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,223	2,444
Natural Gas Storage [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	340	329
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	24	24
Right Of Way [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	25	23
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	34	34
Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	193	$ 99
Sea Robin [Member]
Property, Plant and Equipment [Line Items]
Tangible Asset Impairment Charges	$ 133