Report of Business Segments (Tables)

3 Months Ended

Mar. 31, 2017

Segment Reporting [Abstract]

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

The following tables summarize the results of the Company's business segments during the three months endedMarch 31, 2017 and 2016.

Three Months Ended March 31, 2017	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	456.0	$	—		$	—		$	—		$	456.0
Cost of sales	208.7		—			—			—			208.7
Other operation and maintenance	126.1		0.1			(2.2		)	—			124.0
Depreciation and amortization	54.7		—			0.9			—			55.6
Taxes other than income	22.3		0.2			1.4			—			23.9
Operating income (loss)	44.2		(0.3		)	(0.1		)	—			43.8
Equity in earnings of unconsolidated affiliates	—		35.6			—			—			35.6
Other income (expense)	12.9		0.1			(1.3		)	(0.1		)	11.6
Interest expense	33.6		—			1.5			(0.1		)	35.0
Income tax expense (benefit)	7.3		15.4			(2.7		)	—			20.0
Net income (loss)	$	16.2	$	20.0		$	(0.2	)	$	—		$	36.0
Investment in unconsolidated affiliates	$	—	$	1,158.9		$	—		$	—		$	1,158.9
Total assets	$	8,950.9	$	1,521.2		$	91.1		$	(428.3	)	$	10,134.9

Three Months Ended March 31, 2016	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	433.1	$	—		$	—		$	—		$	433.1
Cost of sales	177.9		—			—			—			177.9
Other operation and maintenance	116.3		0.2			(2.6		)	—			113.9
Depreciation and amortization	76.7		—			1.8			—			78.5
Taxes other than income	23.6		—			1.3			—			24.9
Operating income (loss)	38.6		(0.2		)	(0.5		)	—			37.9
Equity in earnings of unconsolidated affiliates	—		28.3			—			—			28.3
Other income (expense)	5.3		—			0.3			(0.1		)	5.5
Interest expense	35.5		—			0.9			(0.1		)	36.3
Income tax expense (benefit)	2.3		10.1			(2.2		)	—			10.2
Net income	$	6.1	$	18.0		$	1.1		$	—		$	25.2
Investment in unconsolidated affiliates	$	—	$	1,187.4		$	—		$	—		$	1,187.4
Total assets	$	8,288.5	$	1,467.9		$	98.7		$	(331.8	)	$	9,523.3