Quarterly Financial Data (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Data (Unaudited) [Abstract]

Summarized quarterly financial data

25.   Quarterly Financial Data (Unaudited)

Information in any one quarterly period is not indicative of annual results due to the seasonal variations common to the Company's utility operations.  Summarized quarterly financial data for 2011 and 2010 follows:

(In millions, except per share amounts)			Q1		Q2		Q3		Q4
2011
	Operating revenues	$	682.6	$	475.8	$	539.4	$	627.4
	Operating income		103.3		61.6		94.1		111.0
	Net income		44.6		15.1		35.3		46.6
	Earnings per share:
	Basic	$	0.55	$	0.19	$	0.43	$	0.56
	Diluted		0.55		0.18		0.43		0.56
2010
	Operating revenues	$	740.3	$	402.4	$	422.7	$	564.1
	Operating income		116.2		52.1		58.6		89.9
	Net income		63.2		8.7		16.4		45.4
	Earnings per share:
	Basic	$	0.78	$	0.11	$	0.20	$	0.56
	Diluted		0.78		0.11		0.20		0.55