Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Operating revenues:
Sales of natural gas, propane, NGLs and condensate	$ 267	$ 470
Transportation, processing and other	103	79
Gain (Loss) on Derivative Instruments, Net, Pretax	9	19
Total operating revenues	379	568
Operating costs and expenses:
Purchases of natural gas, propane and NGLs	231	402
Operating and maintenance expense	48	47
Depreciation and amortization expense	32	29
General and administrative expense	21	21
Total operating costs and expenses	332	499
Operating Income (Loss)	47	69
Interest expense	(24)	(22)
Earnings from unconsolidated affiliates	49	23
Income before income taxes	72	70
Income tax expense	0	(1)
Net income	72	69
Net income attributable to noncontrolling interests	0	0
Net income attributable to partners	72	69
General partner's interest in net income	(31)	(31)
Net income allocable to limited partners	$ 41	$ 38
Net Income (Loss), Per Outstanding Limited Partnership and General Partnership Unit, Basic and Diluted, Net of Tax	$ 0.36	$ 0.33
Weighted Average Limited Partnership Units Outstanding, Basic	114.7	114.2
Weighted Average Limited Partnership Units Outstanding, Diluted	114.7	114.2
Third Party [Member]
Operating revenues:
Sales of natural gas, propane, NGLs and condensate	$ 105	$ 189
Transportation, processing and other	61	56
Gain (Loss) on Derivative Instruments, Net, Pretax	4	5
Operating costs and expenses:
Purchases of natural gas, propane and NGLs	208	367
General and administrative expense	2	3
Affiliated Entity [Member]
Operating revenues:
Sales of natural gas, propane, NGLs and condensate	162	281
Transportation, processing and other	42	23
Gain (Loss) on Derivative Instruments, Net, Pretax	5	14
Operating costs and expenses:
Purchases of natural gas, propane and NGLs	23	35
General and administrative expense	$ 19	$ 18