Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2023
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 and nine months ended September 30, 2023, are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2023. We have derived our condensed consolidated balance sheet as of December 31, 2022, from the audited consolidated financial statements for the year ended December 31, 2022. 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, 2022. Certain prior year amounts have been reclassified to conform to the current year presentation. 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"). All material intercompany balances and transactions have been eliminated in consolidation.
New Accounting Pronouncements, Policy [Policy Text Block]	Adoption of New Accounting Standards: In the fourth quarter of 2022, we early adopted Accounting Standards Update ("ASU") No. 2020-04, Reference Rate Reform (Topic 848), which provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions that the discontinuation of certain reference rates, including the London Interbank Offered Rate ("LIBOR"), impacts. The adoption of this ASU did not have a material impact on our condensed consolidated financial statements.

Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2023

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 and nine months ended September 30, 2023, are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2023. We have derived our condensed consolidated balance sheet as of December 31, 2022, from the audited consolidated financial statements for the year ended December 31, 2022. 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, 2022. Certain prior year amounts have been reclassified to conform to the current year presentation.

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"). All material intercompany balances and transactions have been eliminated in consolidation.

New Accounting Pronouncements, Policy [Policy Text Block]

Adoption of New Accounting Standards: In the fourth quarter of 2022, we early adopted Accounting Standards Update ("ASU") No. 2020-04, Reference Rate Reform (Topic 848), which provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions that the discontinuation of certain reference rates, including the London Interbank Offered Rate ("LIBOR"), impacts. The adoption of this ASU did not have a material impact on our condensed consolidated financial statements.