Segment Reporting (Tables)

6 Months Ended

Jun. 30, 2015

Segment Reporting [Abstract]

Schedule of Segment Reporting Information

	Six Months Ended June 30,
In thousands	Utility		Gas Storage		Other		Total
2015
Operating revenues	$	389,197	$	10,636	$	112	$	399,945
Depreciation and amortization	37,077		3,264		—		40,341
Income from operations	64,043		1,794		78		65,915
Net income	30,580		28		75		30,683
Capital expenditures	56,273		1,799		—		58,072
Total assets at June 30, 2015	2,646,457		270,509		14,913		2,931,879
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
Total assets at December 31, 2014	$	2,775,011	$	273,813	$	16,121	$	3,064,945

	Three Months Ended June 30,
In thousands	Utility		Gas Storage			Other		Total
2015
Operating revenues	$	132,891	$	5,333		$	56	$	138,280
Depreciation and amortization	18,602		1,628			—		20,230
Income from operations	12,163		739			12		12,914
Net income (loss)	2,245		(86		)	38		2,197
Capital expenditures	30,464		473			—		30,937
2014
Operating revenues	$	128,075	$	5,038		$	56	$	133,169
Depreciation and amortization	18,087		1,622			—		19,709
Income (loss) 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

Schedule of Utility Margin

	Three Months Ended June 30,				Six Months Ended June 30,
In thousands	2015		2014		2015		2014
Utility margin calculation:
Utility operating revenues	$	132,891	$	128,075	$	389,197	$	413,570
Less: Utility cost of gas	62,176		58,280		187,881		213,481
Utility margin	$	70,715	$	69,795	$	201,316	$	200,089