FAIR VALUE MEASUREMENTS (Tables)

9 Months Ended

Sep. 30, 2011

FAIR VALUE MEASUREMENTS [Abstract]

Fair value of assets and liabilities measured on a recurring basis

	Quoted prices in active markets		Significant observable inputs		Significant unobservable inputs
	(Level 1)		(Level 2)		(Level 3)		Total
September 30, 2011
Assets
Money market funds	$	59.0	$	-	$	-	$	59.0
Commodity derivatives		22.0		32.4		7.2		61.6
	$	81.0	$	32.4	$	7.2	$	120.6
Liabilities
Commodity derivatives	$	47.9	$	23.3	$	2.5	$	73.7
Interest rate derivatives		-		13.7		-		13.7
	$	47.9	$	37.0	$	2.5	$	87.4

December 31, 2010
Assets
Money market funds	$	82.9	$	-	$	-	$	82.9
Commodity derivatives		21.3		35.7		9.3		66.3
Interest rate derivative		-		1.0		-		1.0
	$	104.2	$	36.7	$	9.3	$	150.2

Liabilities
Commodity derivatives	$	55.4	$	31.3	$	12.3	$	99.0
Interest rate derivative		-		3.2		-		3.2
	$	55.4	$	34.5	$	12.3	$	102.2
September 30, 2010
Assets
Money market funds	$	128.8	$	-	$	-	$	128.8
Commodity derivatives		42.0		42.4		9.0		93.4
	$	170.8	$	42.4	$	9.0	$	222.2
Liabilities
Commodity derivatives	$	83.1	$	40.6	$	15.9	$	139.6
Interest rate derivatives		-		7.5		-		7.5
	$	83.1	$	48.1	$	15.9	$	147.1

Reconciliation of Level 3 net derivative asset (liability) balances

	Three months ended September 30						Nine months ended September 30
	2011			2010			2011			2010
Beginning of period	$	7.5		$	7.1		$	(3.0	)	$	5.0
Net realized/unrealized gains (losses)
Included in regulatory assets and   liabilities		(3.7	)		(.9	)		1.4			(1.7	)
Included in net income		2.1			4.8			1.6			(2.0	)
Settlements, net of purchases**		(1.9	)		.6			(1.4	)		4.5
Transfers into Level 3		.6			(13.6	)		2.1			(10.8	)
Transfers out of Level 3		.1			(4.9	)		4.0			(1.9	)
End of period	$	4.7		$	(6.9	)	$	4.7		$	(6.9	)
Net unrealized gains (losses) included in net income above relating to derivatives still held at September 30	$	1.2		$	1.7		$	1.3		$	(4.0	)
** There were no purchases for the three and nine months ended September 30, 2011.

Balance sheet classification of margin accounts related to derivative instruments

	September 30		December 31		September 30
	2011		2010		2010
Assets
Margin accounts - derivative instruments	$	27.5	$	50.9	$	58.8
Other - noncurrent		.6		8.1		9.5
Liabilities
Other - current	$	2.2	$	-	$	2.2
Other - noncurrent		.4		-		4.5