Consolidated Balance Sheet (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current Assets:
Cash	$ 173	$ 113
Receivables:
Trade	127,141	137,808
Affiliates	654	2,601
Advances to affiliate	306,910	526,380
Other	3,594	10,364
Transportation and exchange gas receivables	3,485	6,757
Inventories:
Gas in storage, at original cost	715	790
Gas in storage, LIFO	497	1,056
Gas available for customer nomination, at average cost	28,464	8,553
Material and supplies, at lower of average cost or market	37,023	37,133
Regulatory assets	77,810	37,520
Other	14,683	13,451
Total current assets	601,149	782,526
Investments, at cost plus equity in undistributed earnings	47,050	50,262
Property, Plant and Equipment:
Natural gas transmission plant	9,645,382	8,867,626
Less-Accumulated depreciation and amortization	3,257,844	3,090,234
Total property, plant and equipment, net	6,387,538	5,777,392
Other Assets:
Regulatory assets	239,080	256,612
Other	75,066	57,785
Total other assets	314,146	314,397
Total assets	7,349,883	6,924,577
Payables:
Trade	237,873	106,096
Affiliates	37,688	28,268
Cash overdrafts	30,867	8,539
Transportation and exchange gas payables	4,701	3,599
Reserve for rate refunds	0	98,217
Accrued liabilities:
Property and other taxes	13,723	14,180
Interest	19,894	19,894
Regulatory liabilities	7,054	18,014
Customer advances	9,205	17,811
Asset retirement obligations	16,444	35,902
Other	37,785	47,462
Total current liabilities	415,234	397,982
Long-Term Debt	1,428,495	1,428,355
Other Long-Term Liabilities:
Asset retirement obligations	280,031	238,085
Regulatory liabilities	326,083	269,563
Other	35,728	5,307
Total other long-term liabilities	641,842	512,955
Contingent Liabilities and Commitments (Note 2)
Owner's Equity:
Member's capital	2,524,499	2,257,499
Retained earnings	2,339,928	2,328,044
Accumulated other comprehensive loss	(115)	(258)
Total owner's equity	4,864,312	4,585,285
Total liabilities and owner's equity	$ 7,349,883	$ 6,924,577