Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2015

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Benefit Costs

In Millions
	DB Pension Plan						OPEB Plan
Three Months Ended March 31	2015			2014			2015			2014
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	12		$	10		$	6		$	5
Interest expense			25			25			15			14
Expected return on plan assets			(34)			(34)			(23)			(22)
Amortization of:
Net loss			23			15			5			-
Prior service credit			-			-			(10)			(10)
Net periodic cost (credit)		$	26		$	16		$	(7)		$	(13)
Consumers
Net periodic cost (credit)
Service cost		$	12		$	10		$	6		$	5
Interest expense			25			24			14			13
Expected return on plan assets			(33)			(33)			(22)			(21)
Amortization of:
Net loss			22			14			6			1
Prior service credit			-			-			(10)			(10)
Net periodic cost (credit)		$	26		$	15		$	(6)		$	(12)

Consumers Energy Company [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Benefit Costs

In Millions
	DB Pension Plan						OPEB Plan
Three Months Ended March 31	2015			2014			2015			2014
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	12		$	10		$	6		$	5
Interest expense			25			25			15			14
Expected return on plan assets			(34)			(34)			(23)			(22)
Amortization of:
Net loss			23			15			5			-
Prior service credit			-			-			(10)			(10)
Net periodic cost (credit)		$	26		$	16		$	(7)		$	(13)
Consumers
Net periodic cost (credit)
Service cost		$	12		$	10		$	6		$	5
Interest expense			25			24			14			13
Expected return on plan assets			(33)			(33)			(22)			(21)
Amortization of:
Net loss			22			14			6			1
Prior service credit			-			-			(10)			(10)
Net periodic cost (credit)		$	26		$	15		$	(6)		$	(12)