Condensed Consolidated Balance Sheet (Unaudited) (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current Assets:
Cash	$ 100	$ 148
Receivables:
Affiliates	5,074	4,921
Advances to affiliates	208,467	108,838
Others, less allowance of $407 ($406 in 2010)	116,990	110,434
Transportation and exchange gas receivables	10,710	2,417
Inventories	82,009	85,425
Regulatory assets	40,626	48,444
Other	17,787	13,132
Total current assets	481,763	373,759
Investments, at cost plus equity in undistributed earnings	53,292	43,753
Property, Plant and Equipment:
Natural gas transmission plant	7,874,468	7,674,366
Less-Accumulated depreciation and amortization	2,726,787	2,650,133
Total property, plant and equipment, net	5,147,681	5,024,233
Other Assets:
Regulatory assets	199,348	198,921
Other	63,195	59,223
Total other assets	262,543	258,144
Total assets	5,945,279	5,699,889
Payables:
Affiliates	41,171	18,769
Other	125,570	92,647
Transportation and exchange gas payables	2,161	1,646
Accrued liabilities	142,137	119,125
Current maturities of long-term debt	299,986	299,932
Total current liabilities	611,025	532,119
Long-Term Debt	980,591	980,018
Other Long-Term Liabilities:
Asset retirement obligations	226,115	220,644
Regulatory liabilities	154,369	115,563
Other	6,509	6,785
Total other long-term liabilities	386,993	342,992
Contingent liabilities and commitments (Note 2)
Owner's Equity:
Member's capital	1,813,434	1,727,434
Retained earnings	2,153,303	2,117,153
Accumulated other comprehensive income (loss)	(67)	173
Total owner's equity	3,966,670	3,844,760
Total liabilities and owner's equity	$ 5,945,279	$ 5,699,889