Derivative Instruments (Tables)

12 Months Ended

Dec. 31, 2011

Derivative Instruments [Abstract]

Gain/(Loss) Recognized in Income for Derivative Instruments

	Amount of Gain (Loss) on Derivatives Recognized in Income
	Years Ended December 31
Location of Gain (Loss) on Derivatives Recognized in Income	2011			2010		2009
	In Millions
CMS ENERGY
Commodity contracts
Operating revenue	$	2		$	4	$	7
Fuel for electric generation		—			4		(3	)
Cost of gas sold		(2	)		—		(2	)
Purchased and interchange power		—			2		—
Other expense		—			—		(1	)
Interest rate contracts
Other expense		—			—		(1	)
Foreign exchange contracts
Other expense		—			—		(1	)
Total CMS Energy	$	—		$	10	$	(1	)
CONSUMERS
Commodity contracts
Other expense		—			—		(1	)