Condensed Consolidated Balance Sheet (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current Assets:
Cash	$ 0	$ 0
Receivables:
Affiliates	522	489
Advances to affiliate	541,052	811,693
Trade and other	142,526	144,315
Transportation and exchange gas receivables	3,109	1,827
Inventories	75,883	55,209
Regulatory assets	87,996	87,059
Other	13,289	13,305
Total current assets	864,377	1,113,897
Investments, at cost plus equity in undistributed earnings	40,001	42,403
Property, Plant and Equipment:
Natural gas transmission plant	12,818,521	11,996,454
Less-Accumulated depreciation and amortization	3,784,140	3,687,473
Total property, plant and equipment, net	9,034,381	8,308,981
Other Assets:
Regulatory assets	256,274	264,001
Other	123,693	102,198
Total other assets	379,967	366,199
Total Assets	10,318,726	9,831,480
Payables:
Affiliates	33,589	29,455
Trade and other	330,828	251,872
Transportation and exchange gas payables	3,032	1,571
Accrued liabilities	177,184	197,697
Long-term debt due within one year	249,717	0
Total current liabilities	794,350	480,595
Long-Term Debt	1,961,684	2,210,754
Other Long-Term Liabilities:
Asset retirement obligations	266,332	248,518
Regulatory liabilities	483,608	449,391
Advances for construction costs	447,548	283,028
Transportation prepayments	11,358	11,837
Other	6,017	6,088
Total other long-term liabilities	1,214,863	998,862
Contingent Liabilities and Commitments (Note 2)
Owner's Equity:
Member's capital	3,788,499	3,678,499
Retained earnings	2,559,284	2,462,760
Accumulated other comprehensive income	46	10
Total owner's equity	6,347,829	6,141,269
Total liabilities and owner's equity	$ 10,318,726	$ 9,831,480