Retirement Benefits (Tables)

9 Months Ended

Sep. 30, 2014

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Benefit Costs

In Millions
	Pension												OPEB
	Three Months Ended							Nine Months Ended					Three Months Ended							Nine Months Ended
September 30	2014			2013			2014			2013			2014			2013			2014			2013
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	10		$	13		$	30		$	40		$	5		$	5		$	15		$	23
Interest expense			24			23			74			70			14			14			42			52
Expected return on    plan assets			(33)			(32)			(101)			(96)			(22)			(20)			(66)			(58)
Amortization of:
Net loss			14			24			43			72			1			3			2			24
Prior service cost    (credit)			-			1			1			3			(10)			(10)			(31)			(20)
Net periodic cost (credit)		$	15		$	29		$	47		$	89		$	(12)		$	(8)		$	(38)		$	21
Consumers
Net periodic cost (credit)
Service cost		$	10		$	13		$	30		$	39		$	5		$	5		$	15		$	23
Interest expense			24			23			72			69			13			14			40			50
Expected return on    plan assets			(33)			(31)			(99)			(94)			(20)			(19)			(62)			(54)
Amortization of:
Net loss			14			23			42			70			-			3			2			24
Prior service cost    (credit)			-			1			1			3			(10)			(10)			(30)			(20)
Net periodic cost (credit)		$	15		$	29		$	46		$	87		$	(12)		$	(7)		$	(35)		$	23

Consumers Energy Company [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Benefit Costs

In Millions
	Pension												OPEB
	Three Months Ended							Nine Months Ended					Three Months Ended							Nine Months Ended
September 30	2014			2013			2014			2013			2014			2013			2014			2013
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	10		$	13		$	30		$	40		$	5		$	5		$	15		$	23
Interest expense			24			23			74			70			14			14			42			52
Expected return on    plan assets			(33)			(32)			(101)			(96)			(22)			(20)			(66)			(58)
Amortization of:
Net loss			14			24			43			72			1			3			2			24
Prior service cost    (credit)			-			1			1			3			(10)			(10)			(31)			(20)
Net periodic cost (credit)		$	15		$	29		$	47		$	89		$	(12)		$	(8)		$	(38)		$	21
Consumers
Net periodic cost (credit)
Service cost		$	10		$	13		$	30		$	39		$	5		$	5		$	15		$	23
Interest expense			24			23			72			69			13			14			40			50
Expected return on    plan assets			(33)			(31)			(99)			(94)			(20)			(19)			(62)			(54)
Amortization of:
Net loss			14			23			42			70			-			3			2			24
Prior service cost    (credit)			-			1			1			3			(10)			(10)			(30)			(20)
Net periodic cost (credit)		$	15		$	29		$	46		$	87		$	(12)		$	(7)		$	(35)		$	23