Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2019

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Benefit Costs

Presented in the following table are the costs (credits) and other changes in plan assets and benefit obligations incurred in CMS Energy’s and Consumers’ retirement benefits plans:

In Millions
	DB Pension Plans								OPEB Plan
Three Months Ended March 31	2019				2018				2019				2018
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	10			$	12			$	4			$	4
Interest cost		25				22				10				9
Expected return on plan assets		(40		)		(37		)		(22		)		(24		)
Amortization of:
Net loss		12				18				7				4
Prior service cost (credit)		—				1				(16		)		(17		)
Net periodic cost (credit)		$	7			$	16			$	(17	)		$	(24	)
Consumers
Net periodic cost (credit)
Service cost		$	10			$	12			$	3			$	4
Interest cost		23				21				10				8
Expected return on plan assets		(38		)		(35		)		(21		)		(23		)
Amortization of:
Net loss		12				18				7				4
Prior service cost (credit)		—				1				(15		)		(16		)
Net periodic cost (credit)		$	7			$	17			$	(16	)		$	(23	)

Consumers Energy Company

Defined Benefit Plan Disclosure [Line Items]

Schedule Of Net Benefit Costs

Presented in the following table are the costs (credits) and other changes in plan assets and benefit obligations incurred in CMS Energy’s and Consumers’ retirement benefits plans:

In Millions
	DB Pension Plans								OPEB Plan
Three Months Ended March 31	2019				2018				2019				2018
CMS Energy, including Consumers
Net periodic cost (credit)
Service cost		$	10			$	12			$	4			$	4
Interest cost		25				22				10				9
Expected return on plan assets		(40		)		(37		)		(22		)		(24		)
Amortization of:
Net loss		12				18				7				4
Prior service cost (credit)		—				1				(16		)		(17		)
Net periodic cost (credit)		$	7			$	16			$	(17	)		$	(24	)
Consumers
Net periodic cost (credit)
Service cost		$	10			$	12			$	3			$	4
Interest cost		23				21				10				8
Expected return on plan assets		(38		)		(35		)		(21		)		(23		)
Amortization of:
Net loss		12				18				7				4
Prior service cost (credit)		—				1				(15		)		(16		)
Net periodic cost (credit)		$	7			$	17			$	(16	)		$	(23	)