Earnings Per Share - CMS Energy (Tables)

9 Months Ended

Sep. 30, 2011

Earnings Per Share - CMS Energy [Abstract]

Basic and Diluted EPS Computation

	In Millions, Except Per Share Amounts
	Three Months Ended				Nine Months Ended
September 30	2011		2010		2011		2010
Income Available to Common Stockholders
Income from continuing operations	$	140	$	146	$	374	$	335
Less income attributable to noncontrolling interests		1		1		2		3
Less charge for deferred issuance costs on preferred stock		—		8		—		8
Less preferred stock dividends		—		3		—		8
Income from Continuing Operations Available to Common Stockholders — Basic and Diluted	$	139	$	134	$	372	$	316
Average Common Shares Outstanding
Weighted average shares — basic		251.3		229.0		250.5		228.4
Add dilutive contingently convertible securities		11.3		24.9		11.4		21.3
Add dilutive non-vested stock awards and options		0.6		0.2		0.4		0.1
Add dilutive convertible debentures		0.7		0.6		—		—
Weighted average shares — diluted		263.9		254.7		262.3		249.8
Income from Continuing Operations per Average Common Share Available to Common Stockholders
Basic	$	0.55	$	0.58	$	1.48	$	1.38
Diluted		0.53		0.53		1.42		1.26

Schedule of Potential Impacts on the Calculation of Diluted EPS using the If-Converted Method

In Millions
	Nine Months Ended
September 30	2011		2010
Increase to numerator from assumed reduction in interest expense	$	1	$	1
Increase to denominator from assumed conversion of debentures into common shares		0.7		0.7