Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2011

Accounting Policies [Abstract]

Inventories

	2011		2010
	(In thousands)
Aggregates held for resale	$	78,518	$	79,894
Materials and supplies	61,611		57,324
Natural gas in storage (current)	36,578		34,557
Asphalt oil	32,335		25,234
Merchandise for resale	32,165		30,182
Other	32,998		25,706
Total	$	274,205	$	252,897

Property, plant and equipment

	2011		2010		Weighted Average Depreciable Life in  Years
	(Dollars in thousands, where applicable)
Regulated:
Electric:
Generation	$	546,783	$	538,071	47
Distribution	255,232		243,205		36
Transmission	179,580		161,972		44
Other	86,929		83,786		13
Natural gas distribution:
Distribution	1,257,360		1,223,239		38
Other	311,506		285,606		23
Pipeline and energy services:
Transmission	386,227		357,395		52
Gathering	42,378		41,931		19
Storage	41,908		33,967		51
Other	36,179		33,938		29
Nonregulated:
Pipeline and energy services:
Gathering	198,864		203,064		17
Other	13,735		13,512		10
Exploration and production:
Natural gas and oil properties	2,577,576		2,320,967		*
Other	37,570		35,971		9
Construction materials and contracting:
Land	126,790		124,018		—
Buildings and improvements	67,627		65,003		20
Machinery, vehicles and equipment	902,136		899,365		12
Construction in progress	8,085		4,879		—
Aggregate reserves	395,214		393,110		**
Construction services:
Land	4,706		4,526		—
Buildings and improvements	15,001		14,101		22
Machinery, vehicles and equipment	95,891		94,252		7
Other	9,198		10,061		4
Other:
Land	2,837		2,837		—
Other	46,910		29,727		24
Less accumulated depreciation, depletion and amortization	3,361,208		3,103,323
Net property, plant and equipment	$	4,285,014	$	4,115,180

  *  Amortized on the units-of-production method based on total proved reserves at an Mcf equivalent average rate of $2.04, $1.77 and $1.64 for the years ended December 31, 2011, 2010 and 2009, respectively. Includes natural gas and oil properties accounted for under the full-cost method, of which $232.5 and $182.4 million were excluded from amortization at December 31, 2011 and 2010, respectively.

** Depleted on the units-of-production method.

Summary of natural gas and oil properties not subject to amortization

The following table summarizes the Company's natural gas and oil properties not subject to amortization at December 31, 2011, in total and by the year in which such costs were incurred:

			Year Costs Incurred
	Total		2011		2010		2009		2008 and prior
	(In thousands)
Acquisition	$	185,773	$	50,721	$	71,315	$	988	$	62,749
Development	9,938		9,689		156		2		91
Exploration	27,439		24,389		2,710		72		268
Capitalized interest	9,312		3,539		3,096		44		2,633
Total costs not subject to amortization	$	232,462	$	88,338	$	77,277	$	1,106	$	65,741

Schedule of Earnings Per Share Reconciliation [Table Text Block]

Net income was the same for both the basic and diluted earnings per share calculations. A reconciliation of the weighted average common shares outstanding used in the basic and diluted earnings per share calculation was as follows:

	2011	2010	2009	*
	(In thousands)
Weighted average common shares outstanding - basic	188,763	188,137	185,175
Effect of dilutive stock options and performance share awards	142	92	—
Weighted average common shares outstanding - diluted	188,905	188,229	185,175

* Due to the loss on common stock, 825 outstanding stock options, 18 restricted stock grants and 656 performance share awards were excluded from the computation of diluted loss per common share as their effect was antidilutive.

Cash expenditures for interest and income taxes

Cash expenditures for interest and income taxes were as follows:

Years ended December 31,	2011			2010		2009
	(In thousands)
Interest, net of amount capitalized	$	78,133		$	80,962	$	81,267
Income taxes paid (refunded), net	$	(12,287	)	$	46,892	$	39,807

Components of other comprehensive income (loss) and their related tax effects

The components of other comprehensive loss, and their related tax effects for the years ended December 31 were as follows:

	2011			2010			2009
	(In thousands)
Other comprehensive loss:
Net unrealized gain (loss) on derivative instruments qualifying as hedges:
Net unrealized gain (loss) on derivative instruments arising during the period, net of tax of $4,683, $(1,867) and $(2,509) in 2011, 2010 and 2009, respectively	$	7,900		$	(3,077	)	$	(4,094	)
Less: Reclassification adjustment for gain (loss) on derivative instruments included in net income, net of tax of $0, $(2,305) and $29,170 in 2011, 2010 and 2009, respectively	—			(3,750		)	47,590
Net unrealized gain (loss) on derivative instruments qualifying as hedges	7,900			673			(51,684		)
Postretirement liability adjustment, net of tax of $(13,573), $(3,609) and $6,291 in 2011, 2010 and 2009, respectively	(22,427		)	(5,730		)	9,918
Foreign currency translation adjustment, net of tax of $(832), $(3,486) and $6,814 in 2011, 2010 and 2009, respectively	(1,295		)	(5,371		)	10,568
Net unrealized gains on available-for-sale investments, net of tax of $44 in 2011	82			—			—
Total other comprehensive loss	$	(15,740	)	$	(10,428	)	$	(31,198	)

After-tax components of accumulated other comprehensive income (loss)

The after-tax components of accumulated other comprehensive loss as of December 31, 2011, 2010 and 2009, were as follows:

	Net Unrealized Gain (Loss) on Derivative  Instruments  Qualifying as Hedges			Postretirement  Liability Adjustment			Foreign Currency  Translation  Adjustment			Net Unrealized Gains on Available-for-sale Investments		Total Accumulated  Other Comprehensive  Loss
	(In thousands)
Balance at December 31, 2009	$	(2,298	)	$	(25,163	)	$	6,628		$	—	$	(20,833	)
Balance at December 31, 2010	$	(1,625	)	$	(30,893	)	$	1,257		$	—	$	(31,261	)
Balance at December 31, 2011	$	6,275		$	(53,320	)	$	(38	)	$	82	$	(47,001	)