Regulatory Matters (Schedule of PSCR Reconciliation Filings Pending with the MPSC) (Details) (Power Supply Cost Recover (PSCR) [Member], Consumers Energy Company [Member], USD $)
In Millions
12 Months Ended
Dec. 31, 2010
Power Supply Cost Recover (PSCR) [Member] | Consumers Energy Company [Member]
 
Date of FilingMarch 2011
Net Over/(Under) Recovery, Including Interest, Requested by Consumers$ (15)
PSCR Cost of Power Sold$ 1,700.0