Contingencies and Commitments (Tables)
9 Months Ended
Sep. 30, 2011
Guarantees
In Millions  
    Issue     Expiration     Maximum     Carrying  
Guarantee Description   Date     Date     Obligation     Amount  
 
CMS Energy, including Consumers
                                
Indemnity obligations from asset sales and other agreements
   Various     Various through September 2029     $ 512 1   $ 21  
Guarantees and put options2
  Various     Various through March 2021       63       1  
 
Consumers
                                
Guarantees and indemnity obligations
   Various     Various through September 2029     $ 30     $ 1  
 
1   The majority of this amount arises from stock and asset sale agreements under which CMS Energy or a subsidiary of CMS Energy, other than Consumers, indemnified the purchaser for losses resulting from various matters, including claims related to tax disputes, claims related to PPAs, and defects in title to the assets or stock sold to the purchaser by CMS Energy subsidiaries. Except for items described elsewhere in this note, CMS Energy believes the likelihood of material loss to be remote for the indemnity obligations not recorded as liabilities.
2   At September 30, 2011, the carrying amount of CMS Land's put option agreements with certain Bay Harbor property owners was $1 million. If CMS Land is required to purchase a Bay Harbor property under a put option agreement, it may sell the property to recover the amount paid under the put option agreement.
Consumers Energy Company [Member]
 
Guarantees
In Millions  
    Issue     Expiration     Maximum     Carrying  
Guarantee Description   Date     Date     Obligation     Amount  
 
CMS Energy, including Consumers
                                
Indemnity obligations from asset sales and other agreements
   Various     Various through September 2029     $ 512 1   $ 21  
Guarantees and put options2
  Various     Various through March 2021       63       1  
 
Consumers
                                
Guarantees and indemnity obligations
   Various     Various through September 2029     $ 30     $ 1  
 
1   The majority of this amount arises from stock and asset sale agreements under which CMS Energy or a subsidiary of CMS Energy, other than Consumers, indemnified the purchaser for losses resulting from various matters, including claims related to tax disputes, claims related to PPAs, and defects in title to the assets or stock sold to the purchaser by CMS Energy subsidiaries. Except for items described elsewhere in this note, CMS Energy believes the likelihood of material loss to be remote for the indemnity obligations not recorded as liabilities.
2   At September 30, 2011, the carrying amount of CMS Land's put option agreements with certain Bay Harbor property owners was $1 million. If CMS Land is required to purchase a Bay Harbor property under a put option agreement, it may sell the property to recover the amount paid under the put option agreement.