Retirement Benefits (Tables)

6 Months Ended

Jun. 30, 2012

Schedule of Net Benefit Costs

							In Millions
	Pension
	Three Months Ended						Six Months Ended
June 30	2012			2011			2012			2011
CMS Energy, including Consumers
Net periodic pension cost
Service cost		$     12			$     12			$     23			$     24
Interest expense		25			25			50			50
Expected return on plan assets		(32	)		(28	)		(63	)		(56	)
Amortization of:
Net loss		19			15			37			31
Prior service cost		2			2			3			3
Net periodic pension cost		$     26			$     26			$     50			$     52
Consumers
Net periodic pension cost
Service cost		$     11			$     11			$     24			$     23
Interest expense		24			25			48			49
Expected return on plan assets		(31	)		(28	)		(61	)		(55	)
Amortization of:
Net loss		19			16			38			31
Prior service cost		2			2			3			3
Net periodic pension cost		$     25			$     26			$     52			$     51

							In Millions
	OPEB
	Three Months Ended						Six Months Ended
June 30	2012			2011			2012			2011
CMS Energy, including Consumers
Net periodic OPEB cost
Service cost		$       8			$       6			$     16			$     13
Interest expense		20			19			41			38
Expected return on plan assets		(16	)		(16	)		(33	)		(33	)
Amortization of:
Net loss		12			8			23			16
Prior service credit		(5	)		(5	)		(10	)		(10	)
Net periodic OPEB cost		$     19			$     12			$     37			$     24
Consumers
Net periodic OPEB cost
Service cost		$       8			$       7			$     16			$     13
Interest expense		20			19			40			37
Expected return on plan assets		(16	)		(16	)		(31	)		(31	)
Amortization of:
Net loss		12			8			23			16
Prior service credit		(5	)		(5	)		(10	)		(10	)
Net periodic OPEB cost		$     19			$     13			$     38			$     25

Consumers Energy Company [Member]

Schedule of Net Benefit Costs

							In Millions
	Pension
	Three Months Ended						Six Months Ended
June 30	2012			2011			2012			2011
CMS Energy, including Consumers
Net periodic pension cost
Service cost		$     12			$     12			$     23			$     24
Interest expense		25			25			50			50
Expected return on plan assets		(32	)		(28	)		(63	)		(56	)
Amortization of:
Net loss		19			15			37			31
Prior service cost		2			2			3			3
Net periodic pension cost		$     26			$     26			$     50			$     52
Consumers
Net periodic pension cost
Service cost		$     11			$     11			$     24			$     23
Interest expense		24			25			48			49
Expected return on plan assets		(31	)		(28	)		(61	)		(55	)
Amortization of:
Net loss		19			16			38			31
Prior service cost		2			2			3			3
Net periodic pension cost		$     25			$     26			$     52			$     51

							In Millions
	OPEB
	Three Months Ended						Six Months Ended
June 30	2012			2011			2012			2011
CMS Energy, including Consumers
Net periodic OPEB cost
Service cost		$       8			$       6			$     16			$     13
Interest expense		20			19			41			38
Expected return on plan assets		(16	)		(16	)		(33	)		(33	)
Amortization of:
Net loss		12			8			23			16
Prior service credit		(5	)		(5	)		(10	)		(10	)
Net periodic OPEB cost		$     19			$     12			$     37			$     24
Consumers
Net periodic OPEB cost
Service cost		$       8			$       7			$     16			$     13
Interest expense		20			19			40			37
Expected return on plan assets		(16	)		(16	)		(31	)		(31	)
Amortization of:
Net loss		12			8			23			16
Prior service credit		(5	)		(5	)		(10	)		(10	)
Net periodic OPEB cost		$     19			$     13			$     38			$     25