Report of Business Segments (Tables)

12 Months Ended

Dec. 31, 2018

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 for the years ended December 31, 2018, 2017and2016.

2018	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	2,270.3	$	—		$	—		$	—		$	2,270.3
Cost of sales	892.5		—			—			—			892.5
Other operation and maintenance	473.8		1.4			(0.6		)	—			474.6
Depreciation and amortization	321.6		—			—			—			321.6
Taxes other than income	88.2		0.6			3.2			—			92.0
Operating income (loss)	494.2		(2.0		)	(2.6		)	—			489.6
Equity in earnings of unconsolidated affiliates	—		152.8			—			—			152.8
Other income (expense)	25.6		(4.9		)	(3.4		)	(6.0		)	11.3
Interest expense	151.8		—			10.2			(6.0		)	156.0
Income tax expense (benefit)	40.0		37.1			(4.9		)	—			72.2
Net income (loss)	$	328.0	$	108.8		$	(11.3	)	$	—		$	425.5
Investment in unconsolidated affiliates	$	—	$	1,166.6		$	10.9		$	—		$	1,177.5
Total assets	$	9,704.5	$	1,169.8		$	184.8		$	(310.5	)	$	10,748.6
Capital expenditures	$	573.6	$	—		$	—		$	—		$	573.6

2017	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	2,261.1	$	—		$	—		$	—		$	2,261.1
Cost of sales	897.6		—			—			—			897.6
Other operation and maintenance	469.8		(0.8		)	(10.3		)	—			458.7
Depreciation and amortization	280.9		—			2.6			—			283.5
Taxes other than income	84.8		1.0			3.6			—			89.4
Operating income (loss)	528.0		(0.2		)	4.1			—			531.9
Equity in earnings of unconsolidated affiliates	—		131.2			—			—			131.2
Other income (expense)	57.7		(1.0		)	(5.4		)	(0.9		)	50.4
Interest expense	138.4		—			6.3			(0.9		)	143.8
Income tax expense (benefit) (A)	141.8		(195.2		)	4.1			—			(49.3		)
Net income (loss)	$	305.5	$	325.2		$	(11.7	)	$	—		$	619.0
Investment in unconsolidated affiliates	$	—	$	1,151.9		$	8.5		$	—		$	1,160.4
Total assets	$	9,255.6	$	1,155.3		$	109.1		$	(107.3	)	$	10,412.7
Capital expenditures	$	824.1	$	—		$	—		$	—		$	824.1

(A) The Company recorded an income tax benefit of $245.2 million and income tax expense of $10.5 million during the fourth quarter of 2017 due to the Company remeasuring deferred taxes related to the natural gas midstream operations and other operations segments, respectively, as a result of the 2017 Tax Act. See Note 8for further discussion of the effects of the 2017 Tax Act.

2016	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	2,259.2	$	—		$	—		$	—		$	2,259.2
Cost of sales	880.1		—			—			—			880.1
Other operation and maintenance	451.2		(0.1		)	(13.0		)	—			438.1
Depreciation and amortization	316.4		—			6.2			—			322.6
Taxes other than income	84.0		—			3.6			—			87.6
Operating income	527.5		0.1			3.2			—			530.8
Equity in earnings of unconsolidated affiliates	—		101.8			—			—			101.8
Other income (expense)	9.1		(7.7		)	(5.4		)	(0.2		)	(4.2		)
Interest expense	138.1		—			4.2			(0.2		)	142.1
Income tax expense (benefit)	114.4		40.5			(6.8		)	—			148.1
Net income	$	284.1	$	53.7		$	0.4		$	—		$	338.2
Investment in unconsolidated affiliates	$	—	$	1,158.6		$	—		$	—		$	1,158.6
Total assets	$	8,669.4	$	1,521.6		$	89.0		$	(340.4	)	$	9,939.6
Capital expenditures	$	660.1	$	—		$	—		$	—		$	660.1