CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) (USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Operating revenues
Electric	$ 933,490	$ 849,707	$ 2,387,434	$ 2,346,962
Natural gas	122,672	101,203	725,593	733,380
Steam and other	7,772	4,060	28,454	24,621
Total operating revenues	1,063,934	954,970	3,141,481	3,104,963
Operating expenses
Electric fuel and purchased power	413,093	379,871	1,089,106	1,161,835
Cost of natural gas sold and transported	51,104	31,267	450,064	454,097
Cost of sales - steam and other	3,793	3,396	12,903	12,400
Other operating and maintenance expenses	183,152	165,985	540,491	490,703
Demand side management program expenses	29,796	32,228	87,885	99,489
Depreciation and amortization	85,146	72,540	245,392	208,723
Taxes (other than income taxes)	31,428	26,628	100,734	76,906
Total operating expenses	797,512	711,915	2,526,575	2,504,153
Operating income	266,422	243,055	614,906	600,810
Other income, net	1,806	25,949	5,704	27,831
Allowance for funds used during construction - equity	1,956	2,544	5,373	8,801
Interest charges and financing costs
Interest charges - includes other financing costs of $1,798, $1,392, $5,074 and $4,198, respectively	46,955	40,686	138,390	128,125
Allowance for funds used during construction - debt	(853)	(1,111)	(2,399)	(4,202)
Total interest charges and financing costs	46,102	39,575	135,991	123,923
Income before income taxes	224,082	231,973	489,992	513,519
Income taxes	83,364	73,882	181,626	193,493
Net income	$ 140,718	$ 158,091	$ 308,366	$ 320,026