Consolidated Balance Sheet - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current Assets:
Cash	$ 0	$ 0
Receivables:
Trade	167,928	141,726
Affiliates	1,109	489
Advances to affiliate	395,247	811,693
Other	2,494	2,589
Transportation and exchange gas receivables	3,205	1,827
Inventories:
Gas in storage, at original cost	790	786
Gas available for customer nomination, at average cost	1,850	17,233
Materials and supplies, at lower of average cost or market	37,387	37,190
Regulatory assets	97,149	87,059
Other	12,508	13,305
Total current assets	719,667	1,113,897
Investments, at cost plus equity in undistributed earnings	28,505	42,403
Property, Plant and Equipment:
Natural gas transmission plant	13,771,183	11,996,454
Less-Accumulated depreciation and amortization	3,859,520	3,687,473
Total property, plant and equipment, net	9,911,663	8,308,981
Other Assets:
Regulatory assets	276,315	264,001
Other	141,786	102,198
Total other assets	418,101	366,199
Total assets	11,077,936	9,831,480
Payables:
Trade	444,021	211,829
Affiliates	43,420	29,455
Cash overdrafts	25,132	40,043
Transportation and exchange gas payables	2,121	1,571
Accrued liabilities:
Property and other taxes	12,843	13,594
Interest	49,900	49,900
Regulatory liabilities	16,350	9,120
Customer deposits	15,754	47,049
Customer advances	44,689	34,923
Asset retirement obligations	13,676	26,934
Other	20,390	16,177
Long-term debt due within one year	251,430	0
Total current liabilities	939,726	480,595
Long-Term Debt	2,191,576	2,210,754
Other Long-Term Liabilities:
Asset retirement obligations	350,280	248,518
Regulatory liabilities	990,702	449,391
Advances for construction costs	426,771	283,028
Transportation prepayments	10,871	11,837
Deferred revenue	225,858	0
Other	4,828	6,088
Total other long-term liabilities	2,009,310	998,862
Contingent Liabilities and Commitments (Note 2)
Member's Equity:
Member's capital	4,088,499	3,678,499
Retained earnings	1,848,488	2,462,760
Accumulated other comprehensive income	337	10
Total member's equity	5,937,324	6,141,269
Total liabilities and member's equity	$ 11,077,936	$ 9,831,480