Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
OPERATING REVENUES	$ 116,897	$ 116,933	$ 352,914	$ 352,143
OPERATING EXPENSES:
General and administrative	12,337	13,714	39,202	42,913
Operation and maintenance	20,218	19,160	58,701	54,477
Depreciation	25,421	25,190	76,150	75,349
Regulatory debits	873	574	2,593	1,758
Taxes, other than income taxes	4,692	3,995	13,356	12,907
Total operating expenses	63,541	62,633	190,002	187,404
OPERATING INCOME	53,356	54,300	162,912	164,739
OTHER (INCOME) AND OTHER EXPENSES:
Interest expense	8,376	11,506	30,805	34,525
Allowance for equity and borrowed funds used during construction	(454)	(556)	(1,079)	(1,027)
Miscellaneous other (income) expenses, net	176	40	845	(586)
Total other (income) and other expenses	8,098	10,990	30,571	32,912
NET INCOME	45,258	43,310	132,341	131,827
CASH FLOW HEDGES:
Amortization of cash flow hedges into Interest expense	0	(15)	(28)	(46)
COMPREHENSIVE INCOME	$ 45,258	$ 43,295	$ 132,313	$ 131,781