Condensed Consolidated Balance Sheet (Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current Assets:
Cash	$ 146	$ 113
Receivables:
Affiliates	932	2,601
Advances to affiliate	603,014	526,380
Trade and other	127,964	148,172
Transportation and exchange gas receivables	6,386	6,757
Inventories	51,611	47,532
Regulatory assets	42,000	37,520
Other	6,820	13,451
Total current assets	838,873	782,526
Investments, at cost plus equity in undistributed earnings	49,493	50,262
Property, Plant and Equipment:
Natural gas transmission plant	8,940,104	8,867,626
Less-Accumulated depreciation and amortization	3,131,335	3,090,234
Total property, plant and equipment, net	5,808,769	5,777,392
Other Assets:
Regulatory assets	252,633	256,612
Other	66,272	57,785
Total other assets	318,905	314,397
Total Assets	7,016,040	6,924,577
Payables:
Affiliates	28,750	28,268
Trade and other	237,985	114,635
Transportation and exchange gas payables	2,165	3,599
Reserve for rate refunds	0	98,217
Accrued liabilities	147,021	153,263
Total current liabilities	415,921	397,982
Long-Term Debt	1,428,389	1,428,355
Other Long-Term Liabilities:
Asset retirement obligations	238,765	238,085
Regulatory liabilities	288,182	269,563
Other	5,680	5,307
Total other long-term liabilities	532,627	512,955
Contingent Liabilities and Commitments (Note 2)
Owner's Equity:
Member's capital	2,311,499	2,257,499
Retained earnings	2,327,824	2,328,044
Accumulated other comprehensive loss	(220)	(258)
Total owner's equity	4,639,103	4,585,285
Total liabilities and owner's equity	$ 7,016,040	$ 6,924,577