Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2025
Accounting Policies [Abstract]
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation: We have prepared our unaudited condensed consolidated financial statements in accordance with Rule 10-01 of Regulation S-X for interim financial statements. These statements do not include all information and footnotes that generally accepted accounting principles ("GAAP") require for complete annual financial statements. However, the information in these statements reflects all normal recurring adjustments that are, in our opinion, necessary for a fair presentation of the results for the interim periods. The results of operations for the three months ended March 31, 2025, are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2025. We have derived our condensed consolidated balance sheet as of March 31, 2025, from the audited consolidated financial statements for the year ended December 31, 2024. You should read these condensed consolidated financial statements in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2024. The condensed consolidated financial statements include the accounts of MRC Global Inc. and its wholly owned and majority owned subsidiaries (collectively referred to as the "Company" or by terms such as "we", "our" or "us"). The Company is a primary beneficiary of a variable interest entity, and the assets, liabilities and results of operations of the variable interest entity are included in the Company's condensed consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. On December 13, 2024, we entered into a definitive agreement to sell assets associated with our Canada operations to EMCO Corporation, and on March 14, 2025, we completed the sale. The historical results of the assets to be sold and the liabilities to be assumed (the "Disposal Group") have been reflected as discontinued operations in our condensed consolidated financial statements for all periods prior to the definitive agreement. As a result of the executed sale agreement in December of 2024, a pre-tax, non-cash loss on discontinued operations of approximately $22 million was recorded in the fourth quarter of 2024. Upon completion of the sale in March 2025, the cumulative foreign currency translation adjustment of $28 million was released from accumulated other comprehensive income and recognized in the condensed consolidated statement of operations. The total amount was included in loss from discontinued operations, net of tax for the three months ended March 31, 2025. Assets and liabilities associated with the Disposal Group are classified as assets and liabilities of discontinued operations in our condensed consolidated balance sheets as of March 31, 2025 and December 31, 2024. Additional disclosures regarding the sale of assets and assumption of liabilities associated with our Canada operations are provided in Note 2.
New Accounting Pronouncements, Policy [Policy Text Block]	Recently Issued Accounting Standards: In November 2024, the Financial Accounting Standards Board ("FASB") issued ASU 2024-03, Income Statement - Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses ("ASU 2024-03"), which requires public entities to include more detailed disclosures about specific categories of expenses such as inventory purchases, employee compensation, depreciation, amortization and selling costs within the notes to the financial statements. This update will be effective for annual periods beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027. We are currently evaluating the impact of the provisions of ASU 2024-03 on our consolidated financial statements. Adoption of New Accounting Standards: In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740) ("ASU 2023-09"), which aims to enhance the transparency and decision usefulness of income tax disclosures through requiring improvements in those disclosures primarily related to the rate reconciliation and income taxes paid information. This update will be effective for annual periods beginning after December 15, 2024. We adopted ASU 2023-09 on January 1, 2025. We do not expect ASU 2023-09 to impact our consolidated financial statements, and we are currently evaluating the impact of new disclosure requirements beginning with the Form 10-K for the year ended December 31, 2025.

Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2025

Basis of Accounting, Policy [Policy Text Block]

Basis of Presentation: We have prepared our unaudited condensed consolidated financial statements in accordance with Rule 10-01 of Regulation S-X for interim financial statements. These statements do not include all information and footnotes that generally accepted accounting principles ("GAAP") require for complete annual financial statements. However, the information in these statements reflects all normal recurring adjustments that are, in our opinion, necessary for a fair presentation of the results for the interim periods. The results of operations for the three months ended March 31, 2025, are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2025. We have derived our condensed consolidated balance sheet as of March 31, 2025, from the audited consolidated financial statements for the year ended December 31, 2024. You should read these condensed consolidated financial statements in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2024.

The condensed consolidated financial statements include the accounts of MRC Global Inc. and its wholly owned and majority owned subsidiaries (collectively referred to as the "Company" or by terms such as "we", "our" or "us"). The Company is a primary beneficiary of a variable interest entity, and the assets, liabilities and results of operations of the variable interest entity are included in the Company's condensed consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation.

On December 13, 2024, we entered into a definitive agreement to sell assets associated with our Canada operations to EMCO Corporation, and on March 14, 2025, we completed the sale. The historical results of the assets to be sold and the liabilities to be assumed (the "Disposal Group") have been reflected as discontinued operations in our condensed consolidated financial statements for all periods prior to the definitive agreement. As a result of the executed sale agreement in December of 2024, a pre-tax, non-cash loss on discontinued operations of approximately $22 million was recorded in the fourth quarter of 2024. Upon completion of the sale in March 2025, the cumulative foreign currency translation adjustment of $28 million was released from accumulated other comprehensive income and recognized in the condensed consolidated statement of operations. The total amount was included in loss from discontinued operations, net of tax for the three months ended March 31, 2025. Assets and liabilities associated with the Disposal Group are classified as assets and liabilities of discontinued operations in our condensed consolidated balance sheets as of March 31, 2025 and December 31, 2024. Additional disclosures regarding the sale of assets and assumption of liabilities associated with our Canada operations are provided in Note 2.

New Accounting Pronouncements, Policy [Policy Text Block]

Recently Issued Accounting Standards: In November 2024, the Financial Accounting Standards Board ("FASB") issued ASU 2024-03, Income Statement - Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40): Disaggregation of Income Statement Expenses ("ASU 2024-03"), which requires public entities to include more detailed disclosures about specific categories of expenses such as inventory purchases, employee compensation, depreciation, amortization and selling costs within the notes to the financial statements. This update will be effective for annual periods beginning after December 15, 2026 and interim periods within fiscal years beginning after December 15, 2027. We are currently evaluating the impact of the provisions of ASU 2024-03 on our consolidated financial statements.

Adoption of New Accounting Standards: In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740) ("ASU 2023-09"), which aims to enhance the transparency and decision usefulness of income tax disclosures through requiring improvements in those disclosures primarily related to the rate reconciliation and income taxes paid information. This update will be effective for annual periods beginning after December 15, 2024. We adopted ASU 2023-09 on January 1, 2025. We do not expect ASU 2023-09 to impact our consolidated financial statements, and we are currently evaluating the impact of new disclosure requirements beginning with the Form 10-K for the year ended December 31, 2025.