FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

12 Months Ended

Sep. 30, 2015

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair value of financial instruments

The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for the Company are as follows:

					Classification of Estimated Fair Value
	Carrying Amount		Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of September 30, 2015
Cash and cash equivalents	$	13.8	$	13.8	$	13.8	$	—	$	—
Short-term debt	338.0		338.0		—		338.0		—
Long-term debt, including current portion	1,851.5		1,944.2		—		1,944.2		—
As of September 30, 2014
Cash and cash equivalents	$	16.1	$	16.1	$	16.1	$	—	$	—
Short-term debt	287.1		287.1		—		287.1		—
Long-term debt, including current portion	1,851.0		1,937.3		—		1,937.3		—

Laclede Gas

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair value of financial instruments

The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for Laclede Gas are as follows:

					Classification of Estimated Fair Value
	Carrying Amount		Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of September 30, 2015
Cash and cash equivalents	$	1.7	$	1.7	$	1.7	$	—	$	—
Short-term debt	233.0		233.0		—		233.0		—
Long-term debt	808.1		880.2		—		880.2		—
As of September 30, 2014
Cash and cash equivalents	$	3.7	$	3.7	$	3.7	$	—	$	—
Short-term debt	238.6		238.6		—		238.6		—
Long-term debt	807.9		876.2		—		876.2		—

Alagasco

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Fair value of financial instruments

The carrying amounts and estimated fair values of financial instruments not measured at fair value on a recurring basis for Alagasco are as follows:

					Classification of Estimated Fair Value
	Carrying Amount		Fair Value		Quoted Prices in Active Markets (Level 1)		Significant Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of September 30, 2015
Cash and cash equivalents	$	7.2	$	7.2	$	7.2	$	—	$	—
Short-term debt	31.0		31.0		—		31.0		—
Long-term debt, including current portion	250.0		263.2		—		263.2		—
As of September 30, 2014
Cash and cash equivalents	$	5.6	$	5.6	$	5.6	$	—	$	—
Short-term debt	16.0		16.0		—		16.0		—
Long-term debt	249.8		266.4		—		266.4		—