XML 73 R55.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Reportable Segments (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | $ 1,492 |  | $ 1,449 | $ 3,445 |  | $ 3,278 |
Net income (loss) available to common stockholders |  | 139 |  | 92 | 380 |  | 291 |
Plant, property, and equipment, gross |  | 23,258 |  |  | 23,258 |  |  | $ 22,506
Total Assets |  | 23,312 |  |  | 23,312 |  |  | 23,050
Consumers Energy Company |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 1,395 |  | 1,362 | 3,250 |  | 3,099 |
Net income available to common stockholder |  | 151 |  | 103 | 393 |  | 314 |
Plant, property, and equipment, gross |  | 23,059 |  |  | 23,059 |  |  | 22,318
Total Assets |  | 21,283 |  |  | 21,283 |  |  | 21,099
Operating Segments | Electric Utility |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 1,089 |  | 1,077 | 2,167 |  | 2,113 |
Net income (loss) available to common stockholders |  | 130 |  | 94 | 269 |  | 218 |
Plant, property, and equipment, gross | [1] | 15,646 |  |  | 15,646 |  |  | 15,221
Total Assets | [1] | 14,075 |  |  | 14,075 |  |  | 13,906
Operating Segments | Electric Utility | Consumers Energy Company |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 1,089 |  | 1,077 | 2,167 |  | 2,113 |
Net income available to common stockholder |  | 130 |  | 94 | 269 |  | 218 |
Plant, property, and equipment, gross | [1] | 15,646 |  |  | 15,646 |  |  | 15,221
Total Assets | [1] | 14,075 |  |  | 14,075 |  |  | 13,907
Operating Segments | Gas Utility |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 306 |  | 285 | 1,083 |  | 986 |
Net income (loss) available to common stockholders |  | 21 |  | 9 | 124 |  | 96 |
Plant, property, and equipment, gross | [1] | 7,397 |  |  | 7,397 |  |  | 7,080
Total Assets | [1] | 7,187 |  |  | 7,187 |  |  | 7,139
Operating Segments | Gas Utility | Consumers Energy Company |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 306 |  | 285 | 1,083 |  | 986 |
Net income available to common stockholder |  | 21 |  | 9 | 124 |  | 96 |
Plant, property, and equipment, gross | [1] | 7,397 |  |  | 7,397 |  |  | 7,080
Total Assets | [1] | 7,187 |  |  | 7,187 |  |  | 7,139
Operating Segments | Enterprises |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 61 | [2] | 55 | 124 | [2] | 114 |
Net income (loss) available to common stockholders |  | 14 |  | 7 | 29 |  | 19 |
Plant, property, and equipment, gross |  | 175 |  |  | 175 |  |  | 167
Total Assets |  | 321 |  |  | 321 |  |  | 342
Other reconciling items |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 36 | [3] | 32 | 71 | [3] | 65 |
Net income (loss) available to common stockholders |  | (26) |  | $ (18) | (42) |  | $ (42) |
Plant, property, and equipment, gross |  | 40 |  |  | 40 |  |  | 38
Total Assets |  | 1,729 |  |  | 1,729 |  |  | 1,663
Other reconciling items | Consumers Energy Company |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |
Operating Revenue |  | 0 |  |  | 0 |  |  |
Plant, property, and equipment, gross |  | 16 |  |  | 16 |  |  | 17
Total Assets |  | $ 21 |  |  | $ 21 |  |  | $ 53
[1] | Amounts include a portion of Consumers’ other common assets attributable to both the electric and gas utility businesses.
[2] | Amounts represent the enterprises segment’s operating revenue from independent power production and CMS ERM’s sales of energy commodities in support of the independent power production portfolio.
[3] | Amount represents EnerBank’s operating revenue from unsecured consumer installment loans for financing home improvements.

X
- Definition Amount before accumulated depreciation, depletion and amortization and construction in progress of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures. + References No definition available. + Details
Name: | cms_PropertyPlantAndEquipmentGrossExcludingCWIP
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Period end amount of total gross PPE excluding construction work in progress. + References No definition available. + Details
Name: | cms_PublicUtilitiesPropertyPlantAndEquipmentGrossExcludingCWIP
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(12)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(11)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_Assets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(20)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=96947427&loc=d3e1377-109256 + Details
Name: | us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=cms_ElectricUtilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=cms_GasUtilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=cms_EnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=cms_CorporateAndReconcilingItemsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |