New Accounting Standards	9 Months Ended
New Accounting Standards	Sep. 30, 2015
New Accounting Standards	1:New Accounting Standards Implementation of New Accounting Standards ASU 2015‑13, Application of the Normal Purchases and Normal Sales Scope Exception to Certain Electricity Contracts within Nodal Energy Markets: This standard, which became effective in August 2015 for CMS Energy and Consumers, was intended to resolve diversity in practice regarding whether certain electricity contracts are eligible for the normal purchases and sales scope exception from derivative accounting. The standard clarifies that contracts that require transmission of electricity through a market with established price points at each node or hub location are eligible for the scope exception. Consumers applies the normal purchases and sales scope exception to many power purchase agreements that require transmission of electricity through the MISO market, which has price points at various node or hub locations. Since this standard clarifies that these contracts are eligible for the scope exception, which is consistent with Consumers’ treatment, the standard had no impact on CMS Energy’s or Consumers’ consolidated financial statements. New Accounting Standards Not Yet Effective ASU 2014‑09, Revenue from Contracts with Customers: This standard, which will become effective January 1, 2018 for CMS Energy and Consumers, provides new guidance for recognizing revenue from contracts with customers. A primary objective of the standard is to provide a single, comprehensive revenue recognition model that will be applied across entities, industries, and capital markets. The new guidance will replace most of the existing revenue recognition requirements in GAAP, although certain guidance specific to rate-regulated utilities will be retained. Entities will have the option to apply the standard retrospectively to all prior periods presented, or to apply it retrospectively only to contracts existing at the effective date, with the cumulative effect of the standard recorded as an adjustment to beginning retained earnings. CMS Energy and Consumers are evaluating the impact of the standard on their consolidated financial statements. ASU 2014‑12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period: This standard, which will become effective January 1, 2016 for CMS Energy and Consumers, addresses stock awards with performance targets that can be met after an employee has completed the required service period. The standard was intended to resolve diversity in practice regarding the accounting treatment for this type of award. Under the new guidance, the probability of the performance target being met should be factored into compensation expense each period. This guidance is consistent with the accounting that CMS Energy and Consumers already apply to awards of this type. Therefore, CMS Energy and Consumers do not expect the standard to impact their consolidated financial statements. ASU 2015‑02, Amendments to the Consolidation Analysis: This standard, which will become effective January 1, 2016 for CMS Energy and Consumers, provides amended guidance on whether reporting entities should consolidate certain legal entities, including limited partnerships. CMS Energy and Consumers have assessed this standard and do not expect that it will result in any changes to their consolidation conclusions or have any impact on their consolidated income, cash flows, or financial position. ASU 2015‑03, Simplifying the Presentation of Debt Issuance Costs: This standard, which will become effective January 1, 2016 for CMS Energy and Consumers, requires that debt issuance costs be presented as a direct deduction from the carrying amount of long-term debt on the balance sheet. Presently, debt issuance costs are reported as an asset. The new guidance aligns the presentation of debt issuance costs with debt discounts and premiums. The standard is to be applied retrospectively to all prior periods presented. At September 30, 2015, CMS Energy had $42 million of unamortized debt issuance costs, which included $22 million at Consumers. These amounts are recorded in other non‑current assets on the consolidated balance sheets.
Consumers Energy Company [Member]
New Accounting Standards	1:New Accounting Standards Implementation of New Accounting Standards ASU 2015‑13, Application of the Normal Purchases and Normal Sales Scope Exception to Certain Electricity Contracts within Nodal Energy Markets: This standard, which became effective in August 2015 for CMS Energy and Consumers, was intended to resolve diversity in practice regarding whether certain electricity contracts are eligible for the normal purchases and sales scope exception from derivative accounting. The standard clarifies that contracts that require transmission of electricity through a market with established price points at each node or hub location are eligible for the scope exception. Consumers applies the normal purchases and sales scope exception to many power purchase agreements that require transmission of electricity through the MISO market, which has price points at various node or hub locations. Since this standard clarifies that these contracts are eligible for the scope exception, which is consistent with Consumers’ treatment, the standard had no impact on CMS Energy’s or Consumers’ consolidated financial statements. New Accounting Standards Not Yet Effective ASU 2014‑09, Revenue from Contracts with Customers: This standard, which will become effective January 1, 2018 for CMS Energy and Consumers, provides new guidance for recognizing revenue from contracts with customers. A primary objective of the standard is to provide a single, comprehensive revenue recognition model that will be applied across entities, industries, and capital markets. The new guidance will replace most of the existing revenue recognition requirements in GAAP, although certain guidance specific to rate-regulated utilities will be retained. Entities will have the option to apply the standard retrospectively to all prior periods presented, or to apply it retrospectively only to contracts existing at the effective date, with the cumulative effect of the standard recorded as an adjustment to beginning retained earnings. CMS Energy and Consumers are evaluating the impact of the standard on their consolidated financial statements. ASU 2014‑12, Accounting for Share-Based Payments When the Terms of an Award Provide That a Performance Target Could Be Achieved after the Requisite Service Period: This standard, which will become effective January 1, 2016 for CMS Energy and Consumers, addresses stock awards with performance targets that can be met after an employee has completed the required service period. The standard was intended to resolve diversity in practice regarding the accounting treatment for this type of award. Under the new guidance, the probability of the performance target being met should be factored into compensation expense each period. This guidance is consistent with the accounting that CMS Energy and Consumers already apply to awards of this type. Therefore, CMS Energy and Consumers do not expect the standard to impact their consolidated financial statements. ASU 2015‑02, Amendments to the Consolidation Analysis: This standard, which will become effective January 1, 2016 for CMS Energy and Consumers, provides amended guidance on whether reporting entities should consolidate certain legal entities, including limited partnerships. CMS Energy and Consumers have assessed this standard and do not expect that it will result in any changes to their consolidation conclusions or have any impact on their consolidated income, cash flows, or financial position. ASU 2015‑03, Simplifying the Presentation of Debt Issuance Costs: This standard, which will become effective January 1, 2016 for CMS Energy and Consumers, requires that debt issuance costs be presented as a direct deduction from the carrying amount of long-term debt on the balance sheet. Presently, debt issuance costs are reported as an asset. The new guidance aligns the presentation of debt issuance costs with debt discounts and premiums. The standard is to be applied retrospectively to all prior periods presented. At September 30, 2015, CMS Energy had $42 million of unamortized debt issuance costs, which included $22 million at Consumers. These amounts are recorded in other non‑current assets on the consolidated balance sheets.