SEGMENT INFORMATION

We use operating income to measure segment profitability and to allocate resources to our businesses. At September 30, 2018, we reported two segments, which are described below.

Our utility segment includes our electric and natural gas utility operations. Our electric utility operations are engaged in the generation, distribution, and sale of electricity in northeastern Wisconsin. Our natural gas utility operations are engaged in the purchase, distribution, and sale of natural gas to retail customers and the transportation of customer-owned natural gas in northeastern Wisconsin.

The other segment includes non-utility activities, as well as equity earnings from our investment in WRPC.

The following tables show summarized financial information for the three and nine months ended September 30, 2018 and 2017, related to our reportable segments:



(in millions)	Utility		Other			Wisconsin Public Service Corporation Consolidated
Three Months Ended September 30, 2018
Operating revenues	$	379.2	$	—		$	379.2
Other operation and maintenance	114.5		0.1			114.6
Depreciation and amortization	35.7		—			35.7
Operating income (loss)	86.6		(0.2		)	86.4
Other income, net	8.7		0.2			8.9
Interest expense	13.4		—			13.4



(in millions)	Utility		Other			Wisconsin Public Service Corporation Consolidated
Three Months Ended September 30, 2017
Operating revenues	$	380.7	$	—		$	380.7
Other operation and maintenance *	102.5		(0.1		)	102.4
Depreciation and amortization	35.0		0.1			35.1
Operating income *	108.2		—			108.2
Other income, net *	5.4		0.1			5.5
Interest expense	13.7		—			13.7


*	Includes the retroactive restatement impacts of the implementation of ASU 2017-07. See Note 13, Employee Benefits, for more information on this new standard.



(in millions)	Utility		Other			Wisconsin Public Service Corporation Consolidated
Nine Months Ended September 30, 2018
Operating revenues	$	1,122.9	$	—		$	1,122.9
Other operation and maintenance	322.4		0.3			322.7
Depreciation and amortization	105.2		—			105.2
Operating income (loss)	228.5		(0.5		)	228.0
Other income, net	25.5		1.5			27.0
Interest expense	39.4		—			39.4



(in millions)	Utility		Other			Wisconsin Public Service Corporation Consolidated
Nine Months Ended September 30, 2017
Operating revenues	$	1,111.9	$	—		$	1,111.9
Other operation and maintenance *	318.0		0.4			318.4
Depreciation and amortization	103.9		—			103.9
Operating income (loss) *	239.7		(0.4		)	239.3
Other income, net *	15.2		1.9			17.1
Interest expense	41.2		—			41.2


*	Includes the retroactive restatement impacts of the implementation of ASU 2017-07. See Note 13, Employee Benefits, for more information on this new standard.