New Accounting Pronouncements	3 Months Ended
Mar. 31, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements	NEW ACCOUNTING PRONOUNCEMENTS Recently Adopted Pronouncements In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), as amended. This guidance requires a lessee to account for leases as finance or operating leases and disclose key information about leasing arrangements. Both types of leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition, depending on the lease classification. The Registrants adopted the standard on January 1, 2019 using the prospective approach. The standard provides a number of transition practical expedients of which the Registrants elected the package of three expedients that must be taken together, allowing entities to not reassess whether an agreement is a lease, to carryforward the existing lease classification, and to not reassess initial direct costs associated with existing leases; but did not elect to apply hindsight in determining lease term and impairment of the right-of-use assets. The Registrants also elected to not evaluate land easements under the new guidance at adoption if they were not previously accounted for as leases. These practical expedients apply to leases that commenced prior to January 1, 2019. At adoption of the new standard, the Registrants recognized on the Consolidated Statements of Financial Position, right-of-use assets and lease liabilities for certain operating leases of approximately $137 million and $130 million, respectively, for DTE Energy and approximately $74 million and $67 million, respectively, for DTE Electric as of January 1, 2019. The right-of-use lease assets include $9 million of prepaid lease costs that have been reclassified from Other assets, current and noncurrent, and $2 million of deferred lease costs that have been reclassified from Other liabilities, current and noncurrent, for the Registrants. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Statements of Operations, but required additional disclosures for leases. See Note 11 to the Consolidated Financial Statements, "Leases." In February 2018, the FASB issued ASU No. 2018-02, Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings from stranded tax effects resulting from the TCJA. The amendments in this update also require entities to disclose their accounting policy for releasing income tax effects from accumulated other comprehensive income. The Registrants adopted the standard effective January 1, 2019. Upon adoption, DTE Energy reclassified $25 million of income tax effects from Accumulated other comprehensive income (loss) to Retained Earnings. Recently Issued Pronouncements In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments in this update replace the incurred loss impairment methodology in current generally accepted accounting principles with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. Entities will apply the new guidance as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The ASU is effective for the Registrants beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-14, Compensation — Retirement Benefits — Defined Benefit Plans (Subtopic 715-20): Disclosure Framework — Changes to the Disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The amendments in this update modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The ASU is effective for the Registrants for fiscal years ending after December 15, 2020. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract. The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. The amendments in this update modify the requirements for determining whether a decision-making fee is a variable interest and require reporting entities to consider indirect interests held through related parties under common control on a proportional basis. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.

NEW ACCOUNTING PRONOUNCEMENTS

Recently Adopted Pronouncements

In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), as amended. This guidance requires a lessee to account for leases as finance or operating leases and disclose key information about leasing arrangements. Both types of leases will result in the lessee recognizing a right-of-use asset and a corresponding lease liability on its balance sheet, with differing methodology for income statement recognition, depending on the lease classification. The Registrants adopted the standard on January 1, 2019 using the prospective approach. The standard provides a number of transition practical expedients of which the Registrants elected the package of three expedients that must be taken together, allowing entities to not reassess whether an agreement is a lease, to carryforward the existing lease classification, and to not reassess initial direct costs associated with existing leases; but did not elect to apply hindsight in determining lease term and impairment of the right-of-use assets. The Registrants also elected to not evaluate land easements under the new guidance at adoption if they were not previously accounted for as leases. These practical expedients apply to leases that commenced prior to January 1, 2019.

At adoption of the new standard, the Registrants recognized on the Consolidated Statements of Financial Position, right-of-use assets and lease liabilities for certain operating leases of approximately $137 million and $130 million, respectively, for DTE Energy and approximately $74 million and $67 million, respectively, for DTE Electric as of January 1, 2019. The right-of-use lease assets include $9 million of prepaid lease costs that have been reclassified from Other assets, current and noncurrent, and $2 million of deferred lease costs that have been reclassified from Other liabilities, current and noncurrent, for the Registrants. The adoption of the ASU did not have a significant impact on the Registrants' Consolidated Statements of Operations, but required additional disclosures for leases. See Note 11 to the Consolidated Financial Statements, "Leases."

In February 2018, the FASB issued ASU No. 2018-02, Income Statement — Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income. The amendments in this update allow a reclassification from accumulated other comprehensive income to retained earnings from stranded tax effects resulting from the TCJA. The amendments in this update also require entities to disclose their accounting policy for releasing income tax effects from accumulated other comprehensive income. The Registrants adopted the standard effective January 1, 2019. Upon adoption, DTE Energy reclassified $25 million of income tax effects from Accumulated other comprehensive income (loss) to Retained Earnings.

Recently Issued Pronouncements

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments — Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments in this update replace the incurred loss impairment methodology in current generally accepted accounting principles with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. Entities will apply the new guidance as a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is adopted. The ASU is effective for the Registrants beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.

In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurements (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement. The amendments in this update modify the disclosure requirements on fair value measurements in Topic 820. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.

In August 2018, the FASB issued ASU No. 2018-14, Compensation — Retirement Benefits — Defined Benefit Plans (Subtopic 715-20): Disclosure Framework — Changes to the Disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The amendments in this update modify the disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. The ASU is effective for the Registrants for fiscal years ending after December 15, 2020. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.

In August 2018, the FASB issued ASU No. 2018-15, Intangibles — Goodwill and Other — Internal-Use Software (Subtopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That is a Service Contract. The amendments in this update align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software (and hosting arrangements that include an internal use software license). The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.

In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. The amendments in this update modify the requirements for determining whether a decision-making fee is a variable interest and require reporting entities to consider indirect interests held through related parties under common control on a proportional basis. The ASU is effective for the Registrants for fiscal years beginning after December 15, 2019, and interim periods therein. Early adoption is permitted. The Registrants are currently assessing the impact of this standard on their Consolidated Financial Statements.