INFORMATION BY OPERATING SEGMENT (Tables)

12 Months Ended

Sep. 30, 2018

Segment Reporting [Abstract]

Schedule of operating segment information

	Gas Utility		Gas Marketing		Other			Eliminations			Consolidated
2018
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
Gas Utility
Natural and propane gas	842.6		—		—			(72.5		)	770.1
Other operation and maintenance	464.1		—		—			(8.5		)	455.6
Depreciation and amortization	167.0		—		—			—			167.0
Taxes, other than income taxes	152.5		—		—			—			152.5
Total Gas Utility Operating Expenses	1,626.2		—		—			(81.0		)	1,545.2
Gas Marketing and Other *	—		37.8		32.8			69.5			140.1
Total Operating Expenses	1,626.2		37.8		32.8			(11.5		)	1,685.3
Operating Income (Loss)	$	262.2	$	33.8	$	(16.3	)	$	—		$	279.7
Net Economic Earnings (Loss)	$	183.1	$	22.9	$	(22.3	)	$	—		$	183.7
Capital Expenditures	$	457.7	$	—	$	41.7		$	—		$	499.4

	Gas Utility		Gas Marketing		Other			Eliminations			Consolidated
2017
Revenues from external customers	$	1,660.0	$	79.3	$	1.4		$	—		$	1,740.7
Intersegment revenues	7.9		—		6.3			(14.2		)	—
Total Operating Revenues	1,667.9		79.3		7.7			(14.2		)	1,740.7
Operating Expenses
Gas Utility
Natural and propane gas	645.9		—		—			(75.4		)	570.5
Other operation and maintenance	409.1		—		—			(4.1		)	405.0
Depreciation and amortization	153.5		—		—			—			153.5
Taxes, other than income taxes	137.8		—		—			—			137.8
Total Gas Utility Operating Expenses	1,346.3		—		—			(79.5		)	1,266.8
Gas Marketing and Other *	—		74.1		12.8			65.3			152.2
Total Operating Expenses	1,346.3		74.1		12.8			(14.2		)	1,419.0
Operating Income (Loss)	$	321.6	$	5.2	$	(5.1	)	$	—		$	321.7
Net Economic Earnings (Loss)	$	181.5	$	6.8	$	(20.7	)	$	—		$	167.6
Capital Expenditures	$	412.6	$	—	$	25.5		$	—		$	438.1

	Gas Utility		Gas Marketing		Other			Eliminations			Consolidated
2016
Revenues from external customers	$	1,457.2	$	78.5	$	1.6		$	—		$	1,537.3
Intersegment revenues	2.2		—		3.2			(5.4		)	—
Total Operating Revenues	1,459.4		78.5		4.8			(5.4		)	1,537.3
Operating Expenses
Gas Utility
Natural and propane gas	539.7		—		—			(47.5		)	492.2
Other operation and maintenance	379.3		—		—			(1.8		)	377.5
Depreciation and amortization	136.9		—		—			—			136.9
Taxes, other than income taxes	125.2		—		—			—			125.2
Total Gas Utility Operating Expenses	1,181.1		—		—			(49.3		)	1,131.8
Gas Marketing and Other *	—		66.7		12.6			43.9			123.2
Total Operating Expenses	1,181.1		66.7		12.6			(5.4		)	1,255.0
Operating Income (Loss)	$	278.3	$	11.8	$	(7.8	)	$	—		$	282.3
Net Economic Earnings (Loss)	$	160.3	$	6.4	$	(17.6	)	$	—		$	149.1
Capital Expenditures	$	291.7	$	—	$	1.6		$	—		$	293.3

* Operating Expenses for “Gas Marketing and Other” include depreciation and amortization for Gas Marketing ($0.0 for 2018, $0.1 for 2017, and $0.1 for 2016) and for Other ($1.4 for 2018, $0.5 for 2017, and $0.5 for 2016).

Total Assets at End of Year	2018			2017			2016
Gas Utility	$	5,606.7		$	5,551.2		$	5,184.7
Gas Marketing	295.3			246.2			205.0
Other	2,508.0			2,239.5			1,836.6
Eliminations	(1,566.4		)	(1,490.2		)	(1,161.9		)
Total Assets	$	6,843.6		$	6,546.7		$	6,064.4

Schedule of the reconciliation of consolidated net economic earnings to consolidated net income

Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings	2018			2017			2016
Net Income	$	214.2		$	161.6		$	144.2
Adjustments, pre-tax:
Missouri regulatory adjustments	30.6			—			—
Unrealized (gain) loss on energy-related derivatives	(4.0		)	6.0			(0.1		)
Lower of cost or market inventory adjustments	—			—			0.2
Realized gain on economic hedges prior      to the sale of the physical commodity	(0.3		)	(0.3		)	(1.6		)
Acquisition, divestiture and restructuring activities	13.6			4.0			9.2
Income tax effect of adjustments	(10.3		)	(3.7		)	(2.8		)
Effect of the Tax Cuts and Jobs Act	(60.1		)	—			—
Net Economic Earnings	$	183.7		$	167.6		$	149.1