Segment Information

3 Months Ended

Mar. 31, 2014

Segment Reporting [Abstract]

Segment Information [Text Block]

4. SEGMENT INFORMATION

We operate in two primary reportable business segments, local gas distribution and gas storage. We also have other investments and business activities not specifically related to one of these two reporting segments, which we aggregate and report as other. We refer to our local gas distribution business as the utility, and our gas storage segment and other as non-utility. Our utility segment also includes NWN Gas Reserves, which is a wholly-owned subsidiary of Energy Corp, and the utility portion of our Mist underground storage facility in Oregon (Mist). Our gas storage segment includes NWN Gas Storage, which is a wholly-owned subsidiary of NWN Energy, Gill Ranch, which is a wholly-owned subsidiary of NWN Gas Storage, the non-utility portion of Mist, and all third-party asset management services. Other includes NNG Financial and NWN Energy's equity investment in PGH, which is pursuing development of a cross-Cascades pipeline project. See Note 4 in our 2013 Form 10-K for further discussion of our segments.

The following table presents summary financial information concerning the reportable segments. Inter-segment transactions are insignificant:

	Three Months Ended March 31,
In thousands	Utility		Gas Storage		Other			Total
2014
Operating revenues	$	285,495	$	7,835	$	56		$	293,386
Depreciation and amortization	17,967		1,622		—			19,589
Income from operations	71,457		3,553		18			75,028
Net income	36,019		1,627		238			37,884
Capital expenditures	25,350		238		—			25,588
Total assets at March 31, 2014	2,506,930		307,055		16,399			2,830,384
2013
Operating revenues	$	269,659	$	8,146	$	56		$	277,861
Depreciation and amortization	17,188		1,619		—			18,807
Income from operations	70,228		3,957		21			74,206
Net income	36,031		1,636		(28		)	37,639
Capital expenditures	22,388		286		—			22,674
Total assets at March 31, 2013	2,501,724		288,795		15,980			2,806,499
Total assets at December 31, 2013	$	2,644,367	$	310,097	$	16,447		$	2,970,911

Utility Margin

Utility margin is a financial measure consisting of utility operating revenues less revenue taxes and the associated cost of gas. Cost of gas purchased for utility customers is generally a pass-through cost in the amount of revenues billed to regulated utility customers. By netting costs of gas from utility operating revenues, utility margin provides a key metric used by our chief operating decision maker in assessing the performance of the utility segment. The following table presents additional segment information concerning utility margin. The gas storage and other segments emphasize growth in operating revenues and net income as opposed to margin because these segments do not incur commodity cost of sales like the utility and, therefore, use operating revenues and net income to assess performance.

	Three Months Ended March 31,
In thousands	2014		2013
Utility margin calculation:
Utility operating revenues	$	285,495	$	269,659
Less: Utility cost of gas	155,201		142,359
Utility margin	$	130,294	$	127,300