Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating revenues:
Electric, natural gas distribution and pipeline and energy services	$ 491,541	$ 424,124
Exploration and production, construction materials and contracting, construction services and other	551,312	507,480
Total operating revenues	1,042,853	931,604
Operating expenses:
Fuel and purchased power	26,544	21,608
Purchased natural gas sold	244,892	199,187
Operation and maintenance:
Electric, natural gas distribution and pipeline and energy services	67,284	66,101
Exploration and production, construction materials and contracting, construction services and other	445,951	394,019
Depreciation, depletion and amortization	99,557	93,561
Taxes, other than income	55,721	52,597
Total operating expenses	939,949	827,073
Operating income	102,904	104,531
Earnings (loss) from equity method investments	51	(311)
Other income	2,132	1,242
Interest expense	20,971	20,874
Income before income taxes	84,116	84,588
Income taxes	27,932	27,996
Income from continuing operations	56,184	56,592
Loss from discontinued operations, net of tax (Note 9)	(45)	(77)
Net income (loss)	56,139	56,515
Net loss attributable to noncontrolling interest	(523)	0
Dividends declared on preferred stocks	171	171
Earnings on common stock	$ 56,491	$ 56,344
Earnings per common share - basic:
Earnings before discontinued operations	$ 0.30	$ 0.30
Discontinued operations, net of tax	$ 0.00	$ 0.00
Earnings per common share - basic	$ 0.30	$ 0.30
Earnings per common share - diluted:
Earnings before discontinued operations	$ 0.30	$ 0.30
Discontinued operations, net of tax	$ 0.00	$ 0.00
Earnings per common share - diluted	$ 0.30	$ 0.30
Dividends declared per common share	$ 0.1775	$ 0.1725
Weighted average common shares outstanding - basic	189,820	188,831
Weighted average common shares outstanding - diluted	190,432	189,222