XML 152 R105.htm IDEA: XBRL DOCUMENT v2.4.0.6
Stock-Based Compensation (Narrative) (Details)
12 Months Ended
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2009
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period three years    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 6,000,000    
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee 500,000    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 3,884,919    
Consumers Energy Company [Member]
     
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period three years    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized 6,000,000    
Share-based Compensation Arrangement by Share-based Payment Award, Maximum Number of Shares Per Employee 500,000    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 3,884,919    
Minimum [Member]
     
Percent of Initial Grant Issued on Vesting Date 0.00%    
Minimum [Member] | Consumers Energy Company [Member]
     
Percent of Initial Grant Issued on Vesting Date 0.00%    
Maximum [Member]
     
Percent of Initial Grant Issued on Vesting Date 200.00%    
Maximum [Member] | Consumers Energy Company [Member]
     
Percent of Initial Grant Issued on Vesting Date 200.00%    
TSR Restricted Stock [Member]
     
Share Based Compensation Arrangement By Share Based Payment Award, Percentage 75.00% 67.00% 67.00%
TSR Restricted Stock [Member] | Consumers Energy Company [Member]
     
Share Based Compensation Arrangement By Share Based Payment Award, Percentage 75.00% 67.00% 67.00%
Time-Lapsed Restricted Stock [Member]
     
Share Based Compensation Arrangement By Share Based Payment Award, Percentage 25.00% 33.00% 33.00%
Time-Lapsed Restricted Stock [Member] | Consumers Energy Company [Member]
     
Share Based Compensation Arrangement By Share Based Payment Award, Percentage 25.00% 33.00% 33.00%