INFORMATION BY OPERATING SEGMENT (Tables)

12 Months Ended

Sep. 30, 2015

Segment Reporting [Abstract]

Schedule of operating segment information

	Gas Utility		Gas Marketing			Other				Eliminations			Consolidated
2015
Revenues from external customers	$	1,891.8	$	82.9		$	1.7			$	—		$	1,976.4
Intersegment revenues	4.0		70.5			2.0				(76.5		)	—
Total Operating Revenues	1,895.8		153.4			3.7				(76.5		)	1,976.4
Operating Expenses
Gas Utility
Natural and propane gas	957.6		—			—				(75.2		)	882.4
Other operation and maintenance	391.6		—			—				(1.0		)	390.6
Depreciation and amortization	129.9		—			—				—			129.9
Taxes, other than income taxes	142.1		—			—				—			142.1
Total Gas Utility Operating Expenses	1,621.2		—			—				(76.2		)	1,545.0
Gas Marketing and Other	—		146.6		(a)	12.6			(b)	(0.3		)	158.9
Total Operating Expenses	1,621.2		146.6			12.6				(76.5		)	1,703.9
Operating Income (Loss)	274.6		6.8			(8.9		)		—			272.5
Net Economic Earnings (Loss)	150.4		4.2			(16.3		)		—			138.3
Capital Expenditures	284.4		—			5.4				—			289.8

	Gas Utility		Gas Marketing			Other				Eliminations			Consolidated
2014
Revenues from external customers	$	1,462.6	$	162.6		$	2.0			$	—		$	1,627.2
Intersegment revenues	5.2		84.0			1.8				(91.0		)	—
Total Operating Revenues	1,467.8		246.6			3.8				(91.0		)	1,627.2
Operating Expenses
Gas Utility
Natural and propane gas	821.8		—			—				(90.1		)	731.7
Other operation and maintenance	288.7		—			—				(0.9		)	287.8
Depreciation and amortization	82.4		—			—				—			82.4
Taxes, other than income taxes	112.0		—			—				—			112.0
Total Gas Utility Operating Expenses	1,304.9		—			—				(91.0		)	1,213.9
Gas Marketing and Other	—		226.4		(a)	20.5			(b)	—			246.9
Total Operating Expenses	1,304.9		226.4			20.5				(91.0		)	1,460.8
Operating Income (Loss)	162.9		20.2			(16.7		)		—			166.4
Net Economic Earnings (Loss)	92.8		10.2			(2.9		)		—			100.1
Capital Expenditures	168.6		—			2.4				—			171.0

	Gas Utility		Gas Marketing			Other				Eliminations			Consolidated
2013
Revenues from external customers	$	847.2	$	165.1		$	4.7			$	—		$	1,017.0
Intersegment revenues	10.6		24.3			1.5				(36.4		)	—
Total Operating Revenues	857.8		189.4			6.2				(36.4		)	1,017.0
Operating Expenses
Gas Utility
Natural and propane gas	469.1		—			—				(35.7		)	433.4
Other operation and maintenance	180.7		—			—				(0.4		)	180.3
Depreciation and amortization	48.3		—			—				—			48.3
Taxes, other than income taxes	60.1		—			—				—			60.1
Total Gas Utility Operating Expenses	758.2		—			—				(36.1		)	722.1
Gas Marketing and Other	—		176.6		(a)	22.1			(b)	(0.3		)	198.4
Total Operating Expenses	758.2		176.6			22.1				(36.4		)	920.5
Operating Income (Loss)	99.6		12.8			(15.9		)		—			96.5
Net Economic Earnings (Loss)	56.6		8.9			(0.5		)		—			65.0
Capital Expenditures	128.5		—			2.3				—			130.8

(a) Depreciation and amortization for Gas Marketing are included in Gas Marketing Expenses on the Consolidated Statements of Income ($0.3 for 2015, $0.4 for 2014, and $0.3 for 2013).

(b) Depreciation, amortization, and accretion for Other are included in the Other Operating Expenses on the Consolidated Statements of Income ($0.6 for 2015, $0.5 for 2014, and $0.6 for 2013).

Total Assets	2015			2014			2013
Gas Utility	$	4,686.2		$	4,520.0		$	2,981.0
Gas Marketing	160.6			156.7			163.9
Other	1,560.2			1,575.7			115.6
Eliminations	(1,116.8		)	(1,178.4		)	(135.1		)
Total Assets	$	5,290.2		$	5,074.0		$	3,125.4

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

Reconciliation of Consolidated Net Income to Consolidated Net Economic Earnings	2015			2014			2013
Net Income (GAAP)	$	136.9		$	84.6		$	52.8
Unrealized loss (gain) on energy-related derivatives	(1.8		)	(0.9		)	0.5
Lower of cost or market inventory adjustments	0.3			(0.7		)	0.9
Realized (gain) loss on economic hedges prior      to the sale of the physical commodity	1.5			(0.2		)	—
Acquisition, divestiture and restructuring activities	6.1			17.3			10.8
Gain on sale of property	(4.7		)	—			—
Net Economic Earnings (Non-GAAP)	$	138.3		$	100.1		$	65.0