Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2018

Asset Retirement Obligations [Line Items]

Schedule of Asset Retirement Obligations

Presented below are the categories of assets that CMS Energy and Consumers have legal obligations to remove at the end of their useful lives and for which they have an ARO liability recorded:

Company and ARO Description	In-Service Date	Long-Lived Assets
CMS Energy, including Consumers
Closure of gas treating plant and gas wells	various	Gas transmission and storage
Closure of coal ash disposal areas	various	Generating plants coal ash areas
Gas distribution cut, purge, and cap	various	Gas distribution mains and services
Asbestos abatement	1973	Electric and gas utility plant
Closure of renewable generation assets	various	Wind and solar generation facilities
Consumers
Closure of coal ash disposal areas	various	Generating plants coal ash areas
Gas distribution cut, purge, and cap	various	Gas distribution mains and services
Asbestos abatement	1973	Electric and gas utility plant
Closure of renewable generation assets	various	Wind and solar generation facilities

Schedule of Change in Asset Retirement Obligation

Presented in the following tables are the changes in CMS Energy’s and Consumers’ ARO liabilities:

In Millions
	ARO Liability													Cash Flow Revisions			ARO Liability
Company and ARO Description	12/31/2017			Incurred			Settled				Accretion						12/31/2018
CMS Energy, including Consumers
Consumers		$	429		$	17		$	(40	)		$	22		$	—		$	428
Gas treating plant and gas wells		1			—			—				—			—			1
Renewable generation assets		—			3			—				—			—			3
Total CMS Energy		$	430		$	20		$	(40	)		$	22		$	—		$	432
Consumers
Coal ash disposal areas		$	191		$	—		$	(20	)		$	8		$	—		$	179
Gas distribution cut, purge, and cap		186			17			(9		)		11			—			205
Asbestos abatement		42			—			(11		)		2			—			33
Renewable generation assets		10			—			—				1			—			11
Total Consumers		$	429		$	17		$	(40	)		$	22		$	—		$	428

In Millions
	ARO Liability													Cash Flow Revisions		ARO Liability
Company and ARO Description	12/31/2016			Incurred			Settled				Accretion					12/31/2017
CMS Energy, including Consumers
Consumers		$	446		$	5		$	(45	)		$	23		—		$	429
Gas treating plant and gas wells		1			—			—				—			—		1
Total CMS Energy		$	447		$	5		$	(45	)		$	23		—		$	430
Consumers
Coal ash disposal areas		$	201		$	—		$	(18	)		$	8		—		$	191
Gas distribution cut, purge, and cap		182			3			(11		)		12			—		186
Asbestos abatement		56			—			(16		)		2			—		42
Renewable generation assets		7			2			—				1			—		10
Total Consumers		$	446		$	5		$	(45	)		$	23		—		$	429

Consumers Energy Company

Asset Retirement Obligations [Line Items]

Schedule of Asset Retirement Obligations

Presented below are the categories of assets that CMS Energy and Consumers have legal obligations to remove at the end of their useful lives and for which they have an ARO liability recorded:

Company and ARO Description	In-Service Date	Long-Lived Assets
CMS Energy, including Consumers
Closure of gas treating plant and gas wells	various	Gas transmission and storage
Closure of coal ash disposal areas	various	Generating plants coal ash areas
Gas distribution cut, purge, and cap	various	Gas distribution mains and services
Asbestos abatement	1973	Electric and gas utility plant
Closure of renewable generation assets	various	Wind and solar generation facilities
Consumers
Closure of coal ash disposal areas	various	Generating plants coal ash areas
Gas distribution cut, purge, and cap	various	Gas distribution mains and services
Asbestos abatement	1973	Electric and gas utility plant
Closure of renewable generation assets	various	Wind and solar generation facilities

Schedule of Change in Asset Retirement Obligation

Presented in the following tables are the changes in CMS Energy’s and Consumers’ ARO liabilities:

In Millions
	ARO Liability													Cash Flow Revisions			ARO Liability
Company and ARO Description	12/31/2017			Incurred			Settled				Accretion						12/31/2018
CMS Energy, including Consumers
Consumers		$	429		$	17		$	(40	)		$	22		$	—		$	428
Gas treating plant and gas wells		1			—			—				—			—			1
Renewable generation assets		—			3			—				—			—			3
Total CMS Energy		$	430		$	20		$	(40	)		$	22		$	—		$	432
Consumers
Coal ash disposal areas		$	191		$	—		$	(20	)		$	8		$	—		$	179
Gas distribution cut, purge, and cap		186			17			(9		)		11			—			205
Asbestos abatement		42			—			(11		)		2			—			33
Renewable generation assets		10			—			—				1			—			11
Total Consumers		$	429		$	17		$	(40	)		$	22		$	—		$	428

In Millions
	ARO Liability													Cash Flow Revisions		ARO Liability
Company and ARO Description	12/31/2016			Incurred			Settled				Accretion					12/31/2017
CMS Energy, including Consumers
Consumers		$	446		$	5		$	(45	)		$	23		—		$	429
Gas treating plant and gas wells		1			—			—				—			—		1
Total CMS Energy		$	447		$	5		$	(45	)		$	23		—		$	430
Consumers
Coal ash disposal areas		$	201		$	—		$	(18	)		$	8		—		$	191
Gas distribution cut, purge, and cap		182			3			(11		)		12			—		186
Asbestos abatement		56			—			(16		)		2			—		42
Renewable generation assets		7			2			—				1			—		10
Total Consumers		$	446		$	5		$	(45	)		$	23		—		$	429