Report of Business Segments (Tables)

3 Months Ended

Mar. 31, 2019

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, 2019 and 2018.

Three Months Ended March 31, 2019	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	490.0	$	—		$	—		$	—		$	490.0
Cost of sales	212.6		—			—			—			212.6
Other operation and maintenance	120.3		0.4			(1.7		)	—			119.0
Depreciation and amortization	82.4		—			—			—			82.4
Taxes other than income	24.4		0.2			1.7			—			26.3
Operating income (loss)	50.3		(0.6		)	—			—			49.7
Equity in earnings of unconsolidated affiliates	—		30.7			—			—			30.7
Other income (expense)	2.6		(7.4		)	0.7			(0.4		)	(4.5		)
Interest expense	32.4		—			2.6			(0.4		)	34.6
Income tax expense (benefit)	0.9		1.4			(8.1		)	—			(5.8		)
Net income	$	19.6	$	21.3		$	6.2		$	—		$	47.1
Investment in unconsolidated affiliates	$	—	$	1,162.0		$	11.9		$	—		$	1,173.9
Total assets	$	9,478.5	$	1,173.0		$	200.5		$	(90.4	)	$	10,761.6

Three Months Ended March 31, 2018	Electric Utility		Natural Gas Midstream Operations			Other Operations			Eliminations			Total
(In millions)
Operating revenues	$	492.7	$	—		$	—		$	—		$	492.7
Cost of sales	210.5		—			—			—			210.5
Other operation and maintenance	113.6		0.3			(1.2		)	—			112.7
Depreciation and amortization	78.8		—			—			—			78.8
Taxes other than income	22.7		0.2			1.2			—			24.1
Operating income (loss)	67.1		(0.5		)	—			—			66.6
Equity in earnings of unconsolidated affiliates	—		33.9			—			—			33.9
Other income (expense)	4.5		—			(0.7		)	(0.6		)	3.2
Interest expense	37.3		—			1.9			(0.6		)	38.6
Income tax expense (benefit)	3.0		9.8			(2.7		)	—			10.1
Net income	$	31.3	$	23.6		$	0.1		$	—		$	55.0
Investment in unconsolidated affiliates	$	—	$	1,150.6		$	10.0		$	—		$	1,160.6
Total assets	$	9,303.3	$	1,159.0		$	98.3		$	(124.2	)	$	10,436.4