Information by Operating Segment (Tables)

12 Months Ended

Sep. 30, 2020

Segment Reporting [Abstract]

Schedule of Operating Segment Information

2020	Gas Utility		Gas Marketing		Other			Eliminations			Consolidated
Revenues from external customers	$	1,751.8	$	87.9	$	15.7		$	—		$	1,855.4
Intersegment revenues		0.2		—		42.1			(42.3	)		—
Total Operating Revenues		1,752.0		87.9		57.8			(42.3	)		1,855.4
Operating Expenses
Natural gas		660.2		65.1		0.4			(29.6	)		696.1
Other operation and maintenance		421.3		11.8		38.2			(12.7	)		458.6
Depreciation and amortization		189.7		0.6		7.0			—			197.3
Taxes, other than income taxes		146.5		1.1		0.8			—			148.4
Impairments		—		—		148.6			—			148.6
Total Operating Expenses		1,417.7		78.6		195.0			(42.3	)		1,649.0
Operating Income (Loss)	$	334.3	$	9.3	$	(137.2	)	$	—		$	206.4
Net Economic Earnings (Loss)	$	213.4	$	9.1	$	(14.7	)	$	—		$	207.8
Capital Expenditures	$	547.8	$	3.6	$	87.0		$	—		$	638.4

2019	Gas Utility		Gas Marketing		Other			Eliminations			Consolidated
Revenues from external customers	$	1,859.2	$	83.7	$	9.5		$	—		$	1,952.4
Intersegment revenues		1.6		—		12.0			(13.6	)		—
Total Operating Revenues		1,860.8		83.7		21.5			(13.6	)		1,952.4
Operating Expenses
Natural gas		794.6		47.9		0.5			(2.7	)		840.3
Other operation and maintenance		441.7		11.7		31.6			(10.9	)		474.1
Depreciation and amortization		179.4		0.1		2.2			—			181.7
Taxes, other than income taxes		151.7		0.8		1.5			—			154.0
Total Operating Expenses		1,567.4		60.5		35.8			(13.6	)		1,650.1
Operating Income (Loss)	$	293.4	$	23.2	$	(14.3	)	$	—		$	302.3
Net Economic Earnings (Loss)	$	199.8	$	19.4	$	(24.1	)	$	—		$	195.1
Capital Expenditures	$	565.4	$	3.1	$	254.8		$	—		$	823.3

2018	Gas Utility		Gas Marketing		Other			Eliminations			Consolidated
Revenues from external customers	$	1,888.0	$	71.6	$	5.4		$	—		$	1,965.0
Intersegment revenues		0.4		—		11.1			(11.5	)		—
Total Operating Revenues		1,888.4		71.6		16.5			(11.5	)		1,965.0
Operating Expenses
Natural gas		842.6		30.2		0.3			(1.4	)		871.7
Other operation and maintenance		449.7		7.4		30.3			(10.1	)		477.3
Depreciation and amortization		167.0		—		1.4			—			168.4
Taxes, other than income taxes		152.5		0.2		0.8			—			153.5
Total Operating Expenses		1,611.8		37.8		32.8			(11.5	)		1,670.9
Operating Income (Loss)	$	276.6	$	33.8	$	(16.3	)	$	—		$	294.1
Net Economic Earnings (Loss)	$	183.1	$	22.9	$	(22.3	)	$	—		$	183.7
Capital Expenditures	$	457.7	$	—	$	41.7		$	—		$	499.4

Total Assets at End of Year	2020			2019			2018
Gas Utility	$	6,716.2		$	6,094.6		$	5,606.7
Gas Marketing		182.7			212.3			295.3
Other		2,443.5			2,692.7			2,508.0
Eliminations		(1,101.2	)		(1,380.4	)		(1,566.4	)
Total Assets	$	8,241.2		$	7,619.2		$	6,843.6

Schedule of Reconciliation of Consolidated Net Economic Earnings to Consolidated Net Income

Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings	2020			2019			2018
Net Income	$	88.6		$	184.6		$	214.2
Adjustments, pre-tax:
Impairments	148.6				—			—
Provision for ISRS rulings		—			12.2			—
Missouri regulatory adjustments		—			—			30.6
Fair value and timing adjustments		2.5			1.2			(4.3	)
Acquisition, divestiture and restructuring activities		—			0.4			13.6
Income tax effect of adjustments		(31.9	)		(3.3	)		(10.3	)
Effect of the Tax Cuts and Jobs Act		—			—			(60.1	)
Net Economic Earnings	$	207.8		$	195.1		$	183.7