Contingencies And Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Site Contingency [Line Items]

Guarantees

In Millions
			Maximum			Carrying
Guarantee Description	Issue Date	Expiration Date	Obligation			Amount
CMS Energy, including Consumers
Indemnity obligations from stock and    asset sale agreements1	Various	Indefinite		$	153		$	7
Guarantees2	Various	Indefinite			45			-
Consumers
Guarantee2	July 2011	Indefinite		$	30		$	-

1These obligations arose from stock and asset sale agreements under which CMS Energy or a subsidiary of CMS Energy indemnified the purchaser for losses resulting from various matters, primarily claims related to taxes. CMS Energy believes the likelihood of material loss to be remote for the indemnity obligations not recorded as liabilities.

2At Consumers, this obligation comprises a guarantee provided to the U.S. Department of Energy in connection with a settlement agreement regarding damages resulting from the department’s failure to accept spent nuclear fuel from nuclear power plants formerly owned by Consumers. At CMS Energy, the guarantee obligations comprise Consumers’ guarantee to the U.S. Department of Energy and CMS Energy’s 1994 guarantee of non-recourse revenue bonds issued by Genesee. For additional details on this guarantee, see Note 20, Variable Interest Entities.

Purchase Obligations

In Millions
	Payments Due
	Total			2018			2019			2020			2021			2022			Beyond  2022
CMS Energy, including Consumers
Total PPAs		$	9,159		$	1,042		$	1,048		$	1,064		$	1,063		$	795		$	4,147
Other			2,026			891			541			186			61			56			291
Consumers
PPAs
MCV PPA		$	2,621		$	350		$	348		$	346		$	335		$	339		$	903
Palisades PPA			1,647			367			378			388			400			114			-
Related-party PPAs			1,546			87			87			94			96			100			1,082
Other PPAs			3,345			238			235			236			232			242			2,162
Total PPAs		$	9,159		$	1,042		$	1,048		$	1,064		$	1,063		$	795		$	4,147
Other			1,787			859			511			156			48			44			169

Consumers Energy Company [Member]

Site Contingency [Line Items]

Guarantees

In Millions
			Maximum			Carrying
Guarantee Description	Issue Date	Expiration Date	Obligation			Amount
CMS Energy, including Consumers
Indemnity obligations from stock and    asset sale agreements1	Various	Indefinite		$	153		$	7
Guarantees2	Various	Indefinite			45			-
Consumers
Guarantee2	July 2011	Indefinite		$	30		$	-

1These obligations arose from stock and asset sale agreements under which CMS Energy or a subsidiary of CMS Energy indemnified the purchaser for losses resulting from various matters, primarily claims related to taxes. CMS Energy believes the likelihood of material loss to be remote for the indemnity obligations not recorded as liabilities.

2At Consumers, this obligation comprises a guarantee provided to the U.S. Department of Energy in connection with a settlement agreement regarding damages resulting from the department’s failure to accept spent nuclear fuel from nuclear power plants formerly owned by Consumers. At CMS Energy, the guarantee obligations comprise Consumers’ guarantee to the U.S. Department of Energy and CMS Energy’s 1994 guarantee of non-recourse revenue bonds issued by Genesee. For additional details on this guarantee, see Note 20, Variable Interest Entities.

Purchase Obligations

In Millions
	Payments Due
	Total			2018			2019			2020			2021			2022			Beyond  2022
CMS Energy, including Consumers
Total PPAs		$	9,159		$	1,042		$	1,048		$	1,064		$	1,063		$	795		$	4,147
Other			2,026			891			541			186			61			56			291
Consumers
PPAs
MCV PPA		$	2,621		$	350		$	348		$	346		$	335		$	339		$	903
Palisades PPA			1,647			367			378			388			400			114			-
Related-party PPAs			1,546			87			87			94			96			100			1,082
Other PPAs			3,345			238			235			236			232			242			2,162
Total PPAs		$	9,159		$	1,042		$	1,048		$	1,064		$	1,063		$	795		$	4,147
Other			1,787			859			511			156			48			44			169

Manufactured Gas Plant [Member] | Consumers Energy Company [Member]

Site Contingency [Line Items]

Expected Remediation Cost By Year

In Millions
	2018			2019			2020			2021			2022
Consumers
Remediation and other response activity costs		$	17		$	18		$	10		$	18		$	7

Bay Harbor [Member]

Site Contingency [Line Items]

Expected Remediation Cost By Year

In Millions
	2018			2019			2020			2021			2022
CMS Energy
Long-term liquid disposal and operating and maintenance costs		$	5		$	4		$	4		$	4		$	4