XML 87 R56.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Regulatory Matters (Schedule of the Components of PSCR and GCR Over/(Under) Recoveries) (Details) - USD ($) $ in Millions | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | ---
Accrued gas revenue |  | $ 27
Accrued rate refunds | $ 26 | 6
Consumers Energy Company [Member] |  |
Accrued gas revenue |  | 27
Accrued rate refunds | $ 26 | $ 6

X
- Definition Current liabilities that represent obligations to make refunds to customers for fuel costs. + References No definition available. + Details
Name: | cms_AccruedRateRefunds
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount as of the balance sheet date of capitalized fuel costs of a regulated entity that are expected to be recoverable through rate adjustments within one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 980 -SubTopic 340 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6499739&loc=d3e43603-110378 + Details
Name: | us-gaap_DeferredFuelCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | dei_LegalEntityAxis=cms_ConsumersEnergyCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |