Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2021
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of presentation — Our consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information. These statements are unaudited, but in the opinion of management include all adjustments (consisting only of normal recurring adjustments) necessary for a fair statement of the results for the interim periods. The results reported in these consolidated financial statements should not necessarily be taken as indicative of results that may be expected for the entire year. The financial information included herein should be read in conjunction with the consolidated financial statements in Item 8 of our Annual Report on Form 10-K for the year ended December 31, 2020 (the 2020 Form 10-K). Certain prior year amounts have been reclassified to conform to the current presentation.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently adopted accounting pronouncements On January 1, 2021, we adopted Accounting Standards Update (ASU) 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes. This guidance is intended to simplify various aspects of income tax accounting including the elimination of certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. Adoption of this guidance requires certain changes to primarily be made prospectively, with some changes to be made retrospectively. The adoption of this standard did not have a material impact on our consolidated financial statements.
Description of New Accounting Pronouncements Not Yet Adopted [Policy Text Block]	Recently issued accounting pronouncements In March 2020, the FASB issued ASU 2020-04, Facilitation of the Effects of Reference Rate Reform on Financial Reporting and in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform. The guidance is intended to provide temporary optional expedients and exceptions to GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burden related to the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates. The amendments in these ASUs are elective and are effective upon issuance for all entities through December 31, 2022. We are currently assessing the impact of the guidance on our consolidated financial statements.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2021

Basis of Accounting, Policy [Policy Text Block]

Basis of presentation — Our consolidated financial statements are prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information. These statements are unaudited, but in the opinion of management include all adjustments (consisting only of normal recurring adjustments) necessary for a fair statement of the results for the interim periods. The results reported in these consolidated financial statements should not necessarily be taken as indicative of results that may be expected for the entire year. The financial information included herein should be read in conjunction with the consolidated financial statements in Item 8 of our Annual Report on Form 10-K for the year ended December 31, 2020 (the 2020 Form 10-K). Certain prior year amounts have been reclassified to conform to the current presentation.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently adopted accounting pronouncements

On January 1, 2021, we adopted Accounting Standards Update (ASU) 2019-12, Income Taxes – Simplifying the Accounting for Income Taxes. This guidance is intended to simplify various aspects of income tax accounting including the elimination of certain exceptions related to the approach for intraperiod tax allocation, the methodology for calculating income taxes in an interim period and the recognition of deferred tax liabilities for outside basis differences. The new guidance also simplifies aspects of the accounting for franchise taxes and enacted changes in tax laws or rates and clarifies the accounting for transactions that result in a step-up in the tax basis of goodwill. Adoption of this guidance requires certain changes to primarily be made prospectively, with some changes to be made retrospectively. The adoption of this standard did not have a material impact on our consolidated financial statements.

Description of New Accounting Pronouncements Not Yet Adopted [Policy Text Block]

Recently issued accounting pronouncements

In March 2020, the FASB issued ASU 2020-04, Facilitation of the Effects of Reference Rate Reform on Financial Reporting and in January 2021, the FASB issued ASU 2021-01, Reference Rate Reform. The guidance is intended to provide temporary optional expedients and exceptions to GAAP guidance on contract modifications and hedge accounting to ease the financial reporting burden related to the expected market transition from the London Interbank Offered Rate (LIBOR) and other interbank offered rates to alternative reference rates. The amendments in these ASUs are elective and are effective upon issuance for all entities through December 31, 2022. We are currently assessing the impact of the guidance on our consolidated financial statements.