Industry Segment Information (Tables)

12 Months Ended

Dec. 31, 2013

Segment Reporting [Abstract]

Schedule of segment information

Years ended December 31,(in thousands)	2013			2012			2011
Operating revenues from continuing operations
Oil and gas operations	$	1,205,312		$	1,089,230		$	838,160
Natural gas distribution	533,338			451,589			534,953
Total	$	1,738,650		$	1,540,819		$	1,373,113
Operating income (loss) from continuing operations
Oil and gas operations	$	257,963		$	369,765		$	308,561
Natural gas distribution	93,768			93,216			86,216
Eliminations and corporate expenses	(530		)	(1,067		)	(1,078		)
Total	$	351,201		$	461,914		$	393,699
Depreciation, depletion and amortization expense from continuing operations
Oil and gas operations	$	453,474		$	343,183		$	213,841
Natural gas distribution	43,907			42,270			39,916
Total	$	497,381		$	385,453		$	253,757
Interest expense
Oil and gas operations	$	53,981		$	49,958		$	30,907
Natural gas distribution	15,649			16,284			14,740
Eliminations and other	(430		)	(700		)	(825		)
Total	$	69,200		$	65,542		$	44,822
Income tax expense (benefit) from continuing operations
Oil and gas operations	$	71,290		$	115,090		$	100,700
Natural gas distribution	34,687			30,244			26,670
Other	(695		)	(800		)	(1,048		)
Total	$	105,282		$	144,534		$	126,322
Capital expenditures
Oil and gas operations	$	1,104,745		$	1,291,211		$	1,115,452
Natural gas distribution	88,769			71,869			73,984
Total	$	1,193,514		$	1,363,080		$	1,189,436
Identifiable assets
Oil and gas operations	$	5,379,135		$	4,975,170		$	4,046,242
Natural gas distribution	1,193,413			1,177,134			1,163,959
Eliminations and other	49,664			23,586			27,215
Total	$	6,622,212		$	6,175,890		$	5,237,416
Property, plant and equipment, net
Oil and gas operations	$	5,116,958		$	4,697,683		$	3,806,787
Natural gas distribution	885,550			842,685			813,471
Other	1,130			1,268			518
Total	$	6,003,638		$	5,541,636		$	4,620,776