CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating revenues
Electric	$ 2,301,710	$ 2,092,196
Natural gas	879,688	669,596
Other	21,206	21,057
Total operating revenues	3,202,604	2,782,849
Operating expenses
Electric fuel and purchased power	1,067,321	925,043
Cost of natural gas sold and transported	623,828	439,375
Cost of sales — other	9,129	8,411
Operating and maintenance expenses	560,143	529,231
Conservation and demand side management program expenses	77,546	64,032
Depreciation and amortization	245,943	248,706
Taxes (other than income taxes)	124,702	113,427
Total operating expenses	2,708,612	2,328,225
Operating income	493,992	454,624
Other income, net	3,201	3,922
Equity earnings of unconsolidated subsidiaries	7,438	7,577
Allowance for funds used during construction — equity	21,907	19,754
Interest charges and financing costs
Interest charges — includes other financing costs of $5,792 and $5,809, respectively	139,094	139,631
Allowance for funds used during construction — debt	(9,548)	(8,758)
Total interest charges and financing costs	129,546	130,873
Income before income taxes	396,992	355,004
Income taxes	135,771	118,434
Net income	$ 261,221	$ 236,570
Weighted average common shares outstanding:
Basic (in shares)	499,523	489,781
Diluted (in shares)	499,746	490,531
Earnings per average common share:
Basic (in dollars per share)	$ 0.52	$ 0.48
Diluted (in dollars per share)	$ 0.52	$ 0.48
Cash dividends declared per common share (in dollars per share)	$ 0.30	$ 0.27