XML 34 R30.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Regulatory Matters (Narrative) (Details) (USD $) In Millions, unless otherwise specified |  |  | 6 Months Ended |  |  |  | 6 Months Ended | 3 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2014 | Dec. 31, 2013 | Jun. 30, 2014 Consumers Energy Company [Member] | May 31, 2014 Consumers Energy Company [Member] | Dec. 31, 2013 Consumers Energy Company [Member] | Jul. 31, 2014 Consumers Energy Company [Member] Securitization Bonds [Member] Subsequent Event [Member] | Jun. 30, 2014 Coal-Fueled Electric Generation [Member] Consumers Energy Company [Member] site | Jun. 30, 2014 Gas-Fueled Electric Generation [Member] Consumers Energy Company [Member] site | Jun. 30, 2014 Electric Utility [Member] Consumers Energy Company [Member] | Jun. 30, 2014 Gas Utility [Member] Consumers Energy Company [Member] | Mar. 31, 2014 Gas Cost Recover (GCR) [Member] Consumers Energy Company [Member] | Jun. 30, 2014 Gas Cost Recover (GCR) [Member] Consumers Energy Company [Member] | Jun. 30, 2014 Power Supply Cost Recover (PSCR) [Member] Consumers Energy Company [Member]
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Income tax benefits, to be returned to customers |  |  |  |  |  |  |  |  | $ 211 | $ 264 |  |  |
Tax benefit, distribution to customers, term |  |  |  |  |  |  |  |  | 5 years | 12 years |  |  |
Reduction of income tax expense |  |  | 23 |  |  |  |  |  |  |  |  |  |
Accrued Power Supply | 152 |  | 152 |  |  |  |  |  |  |  |  | 72 | 80
Over (under) recovery requested |  |  |  |  |  |  |  |  |  |  | (84) |  |
Energy optimization incentive requested for exceeding savings targets |  |  |  |  | 18 |  |  |  |  |  |  |  |
Requested recovery |  |  |  | 11 |  |  |  |  |  |  |  |  |
Long-term debt | $ 7,535 | $ 7,101 | $ 4,555 |  | $ 4,579 | $ 378 |  |  |  |  |  |  |
Number of units planned to be retired |  |  |  |  |  |  | 7 | 3 |  |  |  |  |

X
- Definition Underrecoveries of power supply and gas costs that represent amounts that will be recovered from customers within one year of the balance sheet date. + References No definition available. + Details
Name: | cms_AccruedPowerSupply
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The total amount of an accelerated return of income tax benefits to customers per regulatory treatment. + References No definition available. + Details
Name: | cms_IncomeTaxBenefitsToBeReturnedToCustomers
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Net over-/(under-) recovery of expense, including interest, requested by Consumers. + References No definition available. + Details
Name: | cms_NetOverUnderRecoveryOfExpenseIncludingInterestRequested
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of units planned to be retired. + References No definition available. + Details
Name: | cms_NumberOfUnitsPlannedToBeRetired
Namespace Prefix: | cms_
Data Type: | xbrli:positiveIntegerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The period reduction to income tax expense due to the accelerated return of income tax benefits to customers per regulatory treatment + References No definition available. + Details
Name: | cms_ReductionOfIncomeTaxExpense
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Energy optimization incentive requested for achieving electric and gas savings targets. + References No definition available. + Details
Name: | cms_RequestedEnergyOptimizationIncentive
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of requested recovery. + References No definition available. + Details
Name: | cms_RequestedRecovery
Namespace Prefix: | cms_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The period covered related to the accelerated return of income tax benefits to customers per regulatory treatment. + References No definition available. + Details
Name: | cms_TaxBenefitDistributionToCustomersTerm
Namespace Prefix: | cms_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount of long-term debt, net of unamortized discount or premium, excluding amounts to be repaid within one year or the normal operating cycle, if longer (current maturities). Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 + Details
Name: | us-gaap_LongTermDebtNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration