Segment Reporting (tables)

12 Months Ended

Dec. 31, 2012

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment [Table Text Block]

In thousands	Utility		Gas Storage		Other			Total
2012
Operating revenues	$	699,862	$	30,520	$	225		$	730,607
Depreciation and amortization	66,545		6,472		—			73,017
Income from operations	128,854		13,226		100			142,180
Net income	55,125		4,521		209			59,855
Capital expenditures	130,151		1,541		337			132,029
Total assets at December 31, 2012	2,511,288		291,568		15,897			2,818,753
2011
Operating revenues	$	801,478	$	26,354	$	223		$	828,055
Depreciation and amortization	63,843		6,161		—			70,004
Income from operations	135,722		9,090		33			144,845
Net income	60,527		4,101		(730		)	63,898
Capital expenditures	94,049		6,485		—			100,534
Total assets at December 31, 2011	2,435,888		294,637		16,049			2,746,574
2010
Operating revenues	$	770,642	$	21,250	$	223		$	792,115
Depreciation and amortization	62,661		2,463		—			65,124
Income from operations	145,688		11,855		62			157,605
Net income	66,262		6,110		295			72,667
Capital expenditures	85,929		161,634		942			248,505

Utility Margin [Table Text Block]

In thousands	2012		2011		2010
Utility margin calculation:
Utility operating revenues	$	699,862	$	801,478	$	770,642
Less: Utility cost of gas	355,335		458,508		424,494
Utility margin	$	344,527	$	342,970	$	346,148