Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 38,795	$ 51,149
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	26,329	25,461
Regulatory debits	939	1,247
Amortization of deferred charges and credits	261	173
Allowance for equity funds used during construction	(317)	(110)
Changes in current assets and liabilities:
Trade and other accounts receivable	1,035	150
Affiliated receivables	(127)	(215)
Exchange gas due from others	208	1,574
Materials and supplies	(17)	(31)
Other current assets	1,542	(277)
Trade accounts payable	(2,242)	(2,949)
Affiliated payables	(5,633)	(2,366)
Exchange gas due to others	(208)	(1,573)
Other accrued liabilities	9,062	11,196
Changes in noncurrent assets and liabilities:
Deferred charges	(1,811)	820
Noncurrent liabilities	7,343	2,554
Net cash provided by operating activities	75,159	86,803
Cash flows from financing activities:
Paymenst for debt issuance costs	(116)	0
Cash distributions to parent	(34,000)	(50,000)
Net cash used in financing activities	(34,116)	(50,000)
Property, plant and equipment:
Capital expenditures, net of equity AFUDC	(11,940)	(12,389)
Contributions and advances for construction costs	1,097	(417)
Disposal of property, plant and equipment, net	(380)	50
Advances to affiliates, net	(29,820)	(24,047)
Net cash used in investing activities	(41,043)	(36,803)
NET INCREASE (DECREASE) IN CASH	0	0
CASH AT BEGINNING OF PERIOD	0	0
CASH AT END OF PERIOD	0	0
Increases to property, plant and equipment	(9,108)	(14,768)
Changes in related in accounts payable and accrued liabilities	(2,832)	2,379
Capital expenditures, net of equity AFUDC	$ (11,940)	$ (12,389)