Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Operating revenues:
Electric, natural gas distribution and pipeline and energy services	$ 1,264,574		$ 1,131,626		$ 1,343,714
Exploration and production, construction materials and contracting, construction services and other	3,197,830		2,943,805		2,706,778
Total operating revenues	4,462,404		4,075,431		4,050,492
Operating expenses:
Fuel and purchased power	83,528		72,380		64,485
Purchased natural gas sold	505,065		425,220		572,187
Operation and maintenance:
Electric, natural gas distribution and pipeline and energy services	269,825		254,194		275,866
Exploration and production, construction materials and contracting, construction services and other	2,535,872		2,377,285		2,215,269
Depreciation, depletion and amortization	386,856		359,205		343,395
Taxes, other than income	188,359		176,140		172,923
Write-downs of oil and natural gas properties (Note 1)	0		391,800		0
Total operating expenses	3,969,505		4,056,224		3,644,125
Operating income	492,899		19,207		406,367
Earnings (loss) from equity method investments	(132)		5,383		4,693
Other income	6,768		6,642		6,520
Interest expense	83,917		76,699		81,354
Income (loss) before income taxes	415,618		(45,467)		336,226
Income taxes	136,736		(31,146)		110,274
Income (loss) from continuing operations	278,882		(14,321)		225,952
Income (loss) from discontinued operations, net of tax (Note 3)	(312)	[1]	13,567	[1]	(12,926)	[1]
Net income (loss)	278,570		(754)		213,026
Net loss attributable to noncontrolling interest	(363)		0		0
Dividends declared on preferred stocks	685		685		685
Earnings (loss) on common stock	$ 278,248		$ (1,439)		$ 212,341
Earnings (loss) per common share - basic:
Earnings (loss) before discontinued operations	$ 1.47		$ (0.08)		$ 1.19
Discontinued operations, net of tax	$ 0.00		$ 0.07		$ (0.07)
Earnings (loss) per common share - basic	$ 1.47		$ (0.01)		$ 1.12
Earnings (loss) per common share - diluted:
Earnings (loss) before discontinued operations	$ 1.47		$ (0.08)		$ 1.19
Discontinued operations, net of tax	$ 0.00		$ 0.07		$ (0.07)
Earnings (loss) per common share - diluted	$ 1.47		$ (0.01)		$ 1.12
Weighted average common shares outstanding - basic	188,855		188,826		188,763
Weighted average common shares outstanding - diluted	189,693		188,826		188,905

[1] Reflected in the Other category.