Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
OPERATING REVENUES	$ 116,188	$ 116,897	$ 351,783	$ 352,914
OPERATING EXPENSES:
General and administrative	12,527	12,337	40,028	39,202
Operation and maintenance	21,294	20,218	55,817	58,701
Depreciation	25,516	25,421	76,345	76,150
Regulatory debits	1,211	873	3,672	2,593
Taxes, other than income taxes	4,056	4,692	13,043	13,356
Total operating expenses	64,604	63,541	188,905	190,002
OPERATING INCOME	51,584	53,356	162,878	162,912
OTHER (INCOME) AND OTHER EXPENSES:
Interest expense	8,139	8,376	24,950	30,805
Allowance for equity and borrowed funds used during construction (AFUDC)	(587)	(454)	(1,099)	(1,079)
Miscellaneous other (income) expenses, net	(30)	176	184	845
Total other (income) and other expenses	7,522	8,098	24,035	30,571
NET INCOME	44,062	45,258	138,843	132,341
CASH FLOW HEDGES:
Amortization of cash flow hedges into Interest expense	0	0	0	(28)
COMPREHENSIVE INCOME	$ 44,062	$ 45,258	$ 138,843	$ 132,313