Segment Information

3 Months Ended

Mar. 31, 2013

Disclosure Segment Information [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” and “other” business segments as “non-utility.” Our utility segment includes NWN Gas Reserves, which is a wholly-owned subsidiary of Energy Corp and the utility portion of our Mist facility. 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 our Mist underground storage facility in Oregon (Mist), and all third-party asset management services. Our “other” segment 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 2012 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 Three Months Ended March 31,
In thousands	Utility		Gas Storage		Other			Total
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 (loss)	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
2012
Operating revenues	$	302,905	$	6,679	$	55		$	309,639
Depreciation and amortization	16,338		1,612		—			17,950
Income from operations	75,964		2,679		23			78,666
Net income	39,468		806		10			40,284
Capital expenditures	19,656		791		—			20,447
Total assets at March 31, 2012	2,420,194		286,756		15,923			2,722,873
Total assets at December 31, 2012	2,505,655		291,568		15,897			2,813,120

Utility margin is a financial measure consisting of utility operating revenues less the associated cost of gas. By netting fluctuating 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 cost of sales like the utility and, therefore, use operating revenues and net income to assess performance.

	Three Months Ended March 31,
In thousands	2013		2012
Utility margin calculation:
Utility operating revenues	$	269,659	$	302,905
Less: Utility cost of gas	142,359		169,755
Utility margin	$	127,300	$	133,150