CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating revenues
Electric	$ 2,092,196	$ 1,936,782
Natural gas	669,596	621,035
Other	21,057	20,262
Total operating revenues	2,782,849	2,578,079
Operating expenses
Electric fuel and purchased power	925,043	863,980
Cost of natural gas sold and transported	439,375	417,946
Cost of sales - other	8,411	7,304
Operating and maintenance expenses	529,231	510,684
Conservation and demand side management program expenses	64,032	63,707
Depreciation and amortization	248,706	228,672
Taxes (other than income taxes)	113,427	105,624
Total operating expenses	2,328,225	2,197,917
Operating income	454,624	380,162
Other income, net	3,922	3,737
Equity earnings of unconsolidated subsidiaries	7,577	7,158
Allowance for funds used during construction - equity	19,754	13,450
Interest charges and financing costs
Interest charges - includes other financing costs of $5,809 and $6,080, respectively	139,613	151,830
Allowance for funds used during construction - debt	(8,758)	(6,607)
Total interest charges and financing costs	130,855	145,223
Income from continuing operations before income taxes	355,022	259,284
Income taxes	118,434	75,515
Income from continuing operations	236,588	183,769
(Loss) income from discontinued operations, net of tax	(18)	124
Net income	$ 236,570	$ 183,893
Weighted average common shares outstanding:
Basic (in shares)	489,781	487,360
Diluted (in shares)	490,531	487,995
Earnings per average common share:
Basic (in dollars per share)	$ 0.48	$ 0.38
Diluted (in dollars per share)	$ 0.48	$ 0.38
Cash dividends declared per common share (in dollars per share)	$ 0.27	$ 0.26