CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Operating revenues
Electric	$ 714,651	$ 749,791	$ 1,396,930	$ 1,453,944
Natural gas	147,398	174,730	530,402	602,921
Steam and other	7,452	8,579	18,221	20,682
Total operating revenues	869,501	933,100	1,945,553	2,077,547
Operating expenses
Electric fuel and purchased power	294,698	352,216	605,597	676,013
Cost of natural gas sold and transported	57,091	94,022	313,968	398,960
Cost of sales - steam and other	2,928	3,989	7,095	9,110
Operating and maintenance expenses	180,100	186,668	348,482	357,339
Demand side management program expenses	29,348	27,767	58,792	58,089
Depreciation and amortization	80,151	80,277	163,740	160,246
Taxes (other than income taxes)	32,875	34,985	66,663	69,306
Total operating expenses	677,191	779,924	1,564,337	1,729,063
Operating income	192,310	153,176	381,216	348,484
Other income, net	1,550	2,235	2,582	3,898
Allowance for funds used during construction - equity	3,548	1,798	6,274	3,417
Interest charges and financing costs
Interest charges - includes other financing costs of $1,790, $1,760, $3,580 and $3,276, respectively	48,074	46,036	96,365	91,435
Allowance for funds used during construction - debt	(1,534)	(820)	(2,695)	(1,546)
Total interest charges and financing costs	46,540	45,216	93,670	89,889
Income before income taxes	150,868	111,993	296,402	265,910
Income taxes	55,461	40,975	107,710	98,262
Net income	$ 95,407	$ 71,018	$ 188,692	$ 167,648