Report of Business Segments (Tables)

3 Months Ended

Mar. 31, 2015

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, 2015 and 2014.

Three Months Ended March 31, 2015	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	480.1	$	—		$	—		$	—		$	480.1
Cost of sales	211.6		—			—			—			211.6
Other operation and maintenance	114.3		0.8			(3.4		)	—			111.7
Depreciation and amortization	73.8		—			2.1			—			75.9
Taxes other than income	23.1		—			1.4			—			24.5
Operating income (loss)	57.3		(0.8		)	(0.1		)	—			56.4
Equity in earnings of unconsolidated affiliates	—		31.7			—			—			31.7
Other income (expense)	2.9		—			2.5			—			5.4
Interest expense	36.8		—			0.6			—			37.4
Income tax expense	6.3		8.1			(1.5		)	—			12.9
Net income (loss)	$	17.1	$	22.8		$	3.3		$	—		$	43.2
Investment in unconsolidated affiliates (at historical cost)	$	—	$	1,315.7		$	—		$	—		$	1,315.7
Total assets	$	8,234.9	$	1,476.7		$	123.0		$	(332.4	)	$	9,502.2

Three Months Ended March 31, 2014	Electric Utility		Natural Gas Midstream Operations		Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	560.4	$	—	$	—		$	—		$	560.4
Cost of sales	293.4		—		—			—			293.4
Other operation and maintenance	117.1		—		(4.7		)	—			112.4
Depreciation and amortization	64.3		—		2.9			—			67.2
Taxes other than income	23.8		—		1.8			—			25.6
Operating income (loss)	61.8		—		—			—			61.8
Equity in earnings of unconsolidated affiliates	—		47.9		—			—			47.9
Other income (expense)	0.4		—		(1.2		)	—			(0.8		)
Interest expense	33.9		—		2.0			—			35.9
Income tax expense	7.6		18.5		(2.4		)	—			23.7
Net income (loss)	$	20.7	$	29.4	$	(0.8	)	$	—		$	49.3
Investment in unconsolidated affiliates (at historical cost)	$	—	$	1,314.2	$	—		$	—		$	1,314.2
Total assets	$	7,826.8	$	1,367.4	$	127.9		$	(71.4	)	$	9,250.7