CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating revenues
Electric	$ 209,502	$ 210,742	$ 425,868	$ 427,051
Natural gas	21,981	19,027	78,481	67,374
Other	271	257	549	532
Total operating revenues	231,754	230,026	504,898	494,957
Operating expenses
Electric fuel and purchased power, non-affiliates	3,562	3,583	6,460	6,456
Purchased power, affiliates	101,629	101,793	202,940	208,251
Cost of natural gas sold and transported	8,507	8,563	37,230	34,550
Operating and maintenance expenses	48,934	48,532	99,278	97,716
Conservation expenses	3,144	3,177	6,122	6,231
Depreciation and amortization	31,449	27,628	62,036	54,677
Taxes (other than income taxes)	7,053	7,005	14,366	13,878
Total operating expenses	204,278	200,281	428,432	421,759
Operating income	27,476	29,745	76,466	73,198
Other expense, net	(509)	(595)	(869)	(1,027)
Allowance for funds used during construction — equity	2,246	1,751	4,101	3,038
Interest charges and financing costs
Interest charges — includes other financing costs of $485 and $461, $963, and $917 respectively	9,763	8,656	19,358	17,338
Allowance for funds used during construction — debt	(1,009)	(749)	(1,845)	(1,299)
Total interest charges and financing costs	8,754	7,907	17,513	16,039
Income before income taxes	20,459	22,994	62,185	59,170
Income taxes	5,270	8,753	15,580	22,510
Net income	$ 15,189	$ 14,241	$ 46,605	$ 36,660