Segment Reporting (tables)

6 Months Ended

Jun. 30, 2014

Segment Reporting [Abstract]

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

	Six Months Ended June 30,
In thousands	Utility		Gas Storage		Other			Total
2014
Operating revenues	$	413,570	$	12,873	$	112		$	426,555
Depreciation and amortization	36,054		3,244		—			39,298
Income from operations	85,192		3,068		34			88,294
Net income	38,224		470		261			38,955
Capital expenditures	52,076		413		—			52,489
Total assets at June 30, 2014	2,487,771		282,939		16,404			2,787,114
2013
Operating revenues	$	393,602	$	15,861	$	112		$	409,575
Depreciation and amortization	34,499		3,238		—			37,737
Income from operations	79,665		7,582		42			87,289
Net income (loss)	36,688		3,088		(11		)	39,765
Capital expenditures	54,522		533		—			55,055
Total assets at June 30, 2013	2,469,320		287,341		15,928			2,772,589
Total assets at December 31, 2013	2,644,367		310,097		16,447			2,970,911

	Three Months Ended June 30,
In thousands	Utility		Gas Storage			Other		Total
2014
Operating revenues	$	128,075	$	5,038		$	56	$	133,169
Depreciation and amortization	18,087		1,622			—		19,709
Income from operations	13,735		(485		)	16		13,266
Net income (loss)	2,205		(1,157		)	23		1,071
Capital expenditures	26,726		175			—		26,901
2013
Operating revenues	$	123,943	$	7,715		$	56	$	131,714
Depreciation and amortization	17,311		1,619			—		18,930
Income from operations	9,437		3,625			21		13,083
Net income	657		1,452			17		2,126
Capital expenditures	32,134		247			—		32,381

Utility Margin [Table Text Block]

	Three Months Ended June 30,				Six Months Ended June 30,
In thousands	2014		2013		2014		2013
Utility margin calculation:
Utility operating revenues	$	128,075	$	123,943	$	413,570	$	393,602
Less: Utility cost of gas	58,280		59,142		213,481		201,501
Utility margin	$	69,795	$	64,801	$	200,089	$	192,101