FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 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
June 30, 2011
Assets
Money market funds	$	59.0	$	-	$	-	$	59.0
Commodity derivatives		11.4		27.4		9.2		48.0
	$	70.4	$	27.4	$	9.2	$	107.0
Liabilities
Commodity derivatives	$	36.5	$	23.2	$	1.7	$	61.4
Interest rate derivatives		-		5.0		-		5.0
	$	36.5	$	28.2	$	1.7	$	66.4

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

	Quoted prices in active markets		Significant observable inputs		Significant unobservable inputs
	(Level 1)		(Level 2)		(Level 3)		Total
June 30, 2010
Assets
Money market funds	$	112.8	$	-	$	-	$	112.8
Commodity derivatives		20.7		27.5		10.2		58.4
	$	133.5	$	27.5	$	10.2	$	171.2
Liabilities
Commodity derivatives	$	56.4	$	50.4	$	3.1	$	109.9
Interest rate derivative		-		4.5		-		4.5
	$	56.4	$	54.9	$	3.1	$	114.4

Reconciliation of Level 3 net derivative asset (liability) balances

Three months ended June 30						Six months ended June 30
	2011			2010			2011			2010
Beginning of period	$	(3.8	)	$	(7.6	)	$	(3.0	)	$	5.0
Net realized/unrealized gains (losses)
Included in regulatory assets and liabilities		2.2			.5			5.1			(.8	)
Included in net income		(.1	)		(.5	)		(.5	)		(6.8	)
Settlements, net of purchases**		2.0			3.1			.5			3.9
Transfers into Level 3		-			2.8			1.5			2.8
Transfers out of Level 3		7.2			8.8			3.9			3.0
End of period	$	7.5		$	7.1		$	7.5		$	7.1
Net unrealized gains (losses) included in net income above relating to derivatives still held at June 30	$	.6		$	(.2	)	$	.5		$	.9
** There were no purchases for the three and six months ended June 30, 2011.

Balance sheet classification of margin accounts related to derivative instruments

	June 30		December 31		June 30
	2011		2010		2010
Assets
Margin accounts - derivative instruments	$	33.8	$	50.9	$	52.6
Other - noncurrent		3.8		8.1		13.5
Liabilities
Other - current	$	.3	$	-	$	1.9
Other - noncurrent		.6		-		3.1