PROPERTY, PLANT AND EQUIPMENT Property, Plant and Equipment - PPE Type (Details) - USD ($) $ in Millions	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 3,338	$ 3,456	$ 3,428	$ 3,403	$ 3,395	$ 3,360	$ 3,331	$ 3,316
Accumulated depreciation	(286)	(342)	(319)	(292)	(269)	(243)	(215)	(192)
Net property, plant and equipment	3,052	$ 3,114	$ 3,109	$ 3,111	3,126	$ 3,117	$ 3,116	$ 3,124
Land and Land Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	8				8
Building and Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	340				340
Pipelines [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	2,387				2,353
Natural Gas Storage [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	329				323
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	24				23
Right Of Way [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	23				23
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	34				33
Linepack [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	57				57
Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	99				192
Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 37				$ 43