New Financial Accounting Standards	9 Months Ended
Sep. 30, 2018
Accounting Changes and Error Corrections [Abstract]
New Financial Accounting Standards	New Financial Accounting Standards In February 2016, the FASB issued amendments on financial reporting of leasing transactions through Accounting Standards Update (ASU) No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The Utilities, as regulated entities, are permitted to continue to recognize expense using the timing that conforms to the regulatory rate treatment. Lessor accounting is similar to the current model, but updated to align with “Revenue from Contracts with Customers (Topic 606)." The amendments are effective, and the Companies plan to adopt the amendments, for reporting periods beginning after December 15, 2018. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients. Upon adoption of the amendments, the Companies expect to elect the following practical expedients: (1) for leases commenced prior to adoption date, the following three transition expedients that will allow the Companies to not reassess: (a) whether expired contracts contain leases; (b) the lease classification for expired leases and (c) the initial direct costs for existing leases; (2) if elected for an underlying asset class, an expedient that will allow the Companies to not apply the recognition requirements to short-term leases and an expedient that will allow the Companies to account for lease and associated non-lease components as a single lease component; (3) an expedient that allows the use of hindsight to determine lease term; and (4) an expedient that will allow the Companies to not evaluate under Topic 842 land easements that exist or expired before the entity’s adoption of Topic 842 and that were not previously accounted for as leases under the current lease standard. For leases currently classified as operating leases, upon adoption of the amendments, the Companies expect to recognize on their balance sheets right-of-use assets and lease liabilities. The adoption of the amendments is not expected to have a material effect on the Companies’ liquidity. The Companies are continuing to evaluate the potential impact of the amendments on the Companies’ results of operations and the additional disclosures required. The Companies will implement additional internal controls related to the amendments, however the adoption of the amendments is not expected to require a change that will materially affect the Companies’ internal control over financial reporting. In August 2017, the FASB issued amendments to the guidance for derivatives and hedging through ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.” The amendments in this update provide greater clarification on hedge accounting for risk components, presentation and disclosure of hedging instruments, and overall targeted improvements to simplify hedge accounting. For public entities, the amendments are effective, and the Companies plan to adopt the amendments, for reporting periods beginning after December 15, 2018. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity. In February 2018, the FASB issued amendments to the guidance for reporting comprehensive income through ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The amendments allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the TCJA. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Companies are electing to adopt the amendments in the fourth quarter of 2018. The impact of adoption on the Companies’ financial position, results of operations and liquidity is expected to be immaterial. In August 2018, the FASB issued amendments to the guidance for internal use software through ASU 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 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. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Companies elected to adopt the amendments in the third quarter of 2018, prospectively for all in-scope implementation costs incurred after the date of adoption. The impact of adoption on the Companies’ financial position, results of operations and liquidity was immaterial.

New Financial Accounting Standards

In February 2016, the FASB issued amendments on financial reporting of leasing transactions through Accounting Standards Update (ASU) No. 2016-02, “Leases (Topic 842)." The amendments require lessees to recognize assets and liabilities on the balance sheet and disclose key information about leasing arrangements. Lessees will need to recognize a right-of-use asset and a lease liability for virtually all of their leases (other than leases that meet the definition of a short-term lease). The Utilities, as regulated entities, are permitted to continue to recognize expense using the timing that conforms to the regulatory rate treatment. Lessor accounting is similar to the current model, but updated to align with “Revenue from Contracts with Customers (Topic 606)." The amendments are effective, and the Companies plan to adopt the amendments, for reporting periods beginning after December 15, 2018. The amendments must be adopted using a modified retrospective transition and provide for certain practical expedients.

Upon adoption of the amendments, the Companies expect to elect the following practical expedients: (1) for leases commenced prior to adoption date, the following three transition expedients that will allow the Companies to not reassess: (a) whether expired contracts contain leases; (b) the lease classification for expired leases and (c) the initial direct costs for existing leases; (2) if elected for an underlying asset class, an expedient that will allow the Companies to not apply the recognition requirements to short-term leases and an expedient that will allow the Companies to account for lease and associated non-lease components as a single lease component; (3) an expedient that allows the use of hindsight to determine lease term; and (4) an expedient that will allow the Companies to not evaluate under Topic 842 land easements that exist or expired before the entity’s adoption of Topic 842 and that were not previously accounted for as leases under the current lease standard. For leases currently classified as operating leases, upon adoption of the amendments, the Companies expect to recognize on their balance sheets right-of-use assets and lease liabilities. The adoption of the amendments is not expected to have a material effect on the Companies’ liquidity. The Companies are continuing to evaluate the potential impact of the amendments on the Companies’ results of operations and the additional disclosures required. The Companies will implement additional internal controls related to the amendments, however the adoption of the amendments is not expected to require a change that will materially affect the Companies’ internal control over financial reporting.

In August 2017, the FASB issued amendments to the guidance for derivatives and hedging through ASU 2017-12, “Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities.” The amendments in this update provide greater clarification on hedge accounting for risk components, presentation and disclosure of hedging instruments, and overall targeted improvements to simplify hedge accounting. For public entities, the amendments are effective, and the Companies plan to adopt the amendments, for reporting periods beginning after December 15, 2018. The Companies are in the process of evaluating the potential impact of the new guidance on the Companies’ financial position, results of operations and liquidity.

In February 2018, the FASB issued amendments to the guidance for reporting comprehensive income through ASU 2018-02, “Income Statement-Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income.” The amendments allow a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the TCJA. For public entities, the amendments are effective for reporting periods beginning after December 15, 2018, with early adoption permitted. The Companies are electing to adopt the amendments in the fourth quarter of 2018. The impact of adoption on the Companies’ financial position, results of operations and liquidity is expected to be immaterial.

In August 2018, the FASB issued amendments to the guidance for internal use software through ASU 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 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. For public entities, the amendments are effective for reporting periods beginning after December 15, 2019, with early adoption permitted. The Companies elected to adopt the amendments in the third quarter of 2018, prospectively for all in-scope implementation costs incurred after the date of adoption. The impact of adoption on the Companies’ financial position, results of operations and liquidity was immaterial.