Background and Basis of Presentation (Policy)	3 Months Ended
Mar. 31, 2020
Background and Basis of Presentation [Abstract]
Business Operations	Business Operations: MRC Global Inc. is a holding company headquartered in Houston, Texas. Our wholly owned subsidiaries are global distributors of pipe, valves, fittings (“PVF”) and related infrastructure products and services across each of the upstream production (exploration, production and extraction of underground oil and gas), midstream pipeline (gathering and transmission of oil and gas), gas utilities (gas utilities and the storage and distribution of oil and gas) and downstream and industrial (crude oil refining and petrochemical and chemical processing and general industrials) sectors. We have branches in principal industrial, hydrocarbon producing and refining areas throughout the United States, Canada, Europe, Asia, Australasia, the Middle East and Caspian. We obtain products from a broad range of suppliers.
Basis of Presentation	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 require for complete annual financial statements. However, the information in these statements reflects all normal recurring adjustments which 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, 2020 are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2020. We have derived our condensed consolidated balance sheet as of December 31, 2019 from the audited consolidated financial statements for the year ended December 31, 2019. 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, 2019. The 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 such terms as “we,” “our” or “us”). All material intercompany balances and transactions have been eliminated in consolidation.
Adoption of New Accounting Standards and Recently Issued Accounting Standards	Recent Issued Accounting Pronouncements: In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-04, Reference Rate Reform (Topic 848) ("ASU 2020-04"), which provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by the discontinuation of the London Interbank Offered Rate ("LIBOR") or by another reference rate expected to be discontinued. The amendments are effective for all entities as of March 12, 2020 through December 31, 2022. We are currently evaluating the impacts of the the provisions of ASU 2020-04 on our consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, an update intended to simplify various aspects related to accounting for income taxes. This guidance removes certain exceptions to the general principles in Topic 740 and clarifies and amends existing guidance to improve consistent application. This accounting standards update will be effective for annual and interim financial statement periods beginning after December 15, 2020, with early adoption permitted. We are currently evaluating the impact of this accounting standards update, but do not expect the adoption to materially impact our consolidated financial statements. Adoption of New Accounting Standards: In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments, which requires that an entity measure impairment of certain financial instruments, including trade receivables, based on expected losses rather than incurred losses. We adopted ASU 2016-13 on January 1, 2020. The adoption of this new standard resulted in the recognition of $1 million of incremental bad debt expense in the three months ended March 31, 2020.
Valuation of Goodwill and Indefinite-Lived Intangibles	Valuation of Goodwill and Indefinite-Lived Intangibles: We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. Our October 2019 quantitative impairment tests for goodwill and indefinite-lived intangible assets indicated there was no impairment as the fair value of each of our reporting units and indefinite-lived intangible assets exceeded carrying value by a significant margin, with the exception of our International reporting unit for which the excess was approximately 20%. As a result of our reduced forecasts and the significant decline in our market capitalization as a result of the coronavirus disease 2019 (“COVID-19”) pandemic, we qualitatively assessed whether it was more likely than not our goodwill or indefinite-lived intangible assets were impaired as of March 31, 2020. We reviewed our previous forecasts and assumptions based on our current projections that are subject to various risks and uncertainties, including: (1) forecasted revenues, expenses and cash flows, including the duration and extent of impact to our business from the COVID-19 pandemic, (2) current discount rates, (3) the reduction in our market capitalization, and (4) control premiums on observable market conditions. Based on our qualitative assessment, we concluded that our goodwill and indefinite-lived intangible assets were not impaired as of March 31, 2020. However, we are unable to predict how long current market conditions will persist, what additional measures may be introduced by governments or private parties or what effect any such additional measures may have on our business. To the extent we are unable to conclude in a future period that it is more likely than not our goodwill and indefinite-lived intangible assets are not impaired, we would be required to perform a full quantitative impairment test, the results of which could require recognition of an impairment charge in future periods.

Background and Basis of Presentation (Policy)

3 Months Ended

Mar. 31, 2020

Background and Basis of Presentation [Abstract]

Business Operations: MRC Global Inc. is a holding company headquartered in Houston, Texas. Our wholly owned subsidiaries are global distributors of pipe, valves, fittings (“PVF”) and related infrastructure products and services across each of the upstream production (exploration, production and extraction of underground oil and gas), midstream pipeline (gathering and transmission of oil and gas), gas utilities (gas utilities and the storage and distribution of oil and gas) and downstream and industrial (crude oil refining and petrochemical and chemical processing and general industrials) sectors. We have branches in principal industrial, hydrocarbon producing and refining areas throughout the United States, Canada, Europe, Asia, Australasia, the Middle East and Caspian. We obtain products from a broad range of suppliers.

Basis of Presentation

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 require for complete annual financial statements. However, the information in these statements reflects all normal recurring adjustments which 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, 2020 are not necessarily indicative of the results that will be realized for the fiscal year ending December 31, 2020. We have derived our condensed consolidated balance sheet as of December 31, 2019 from the audited consolidated financial statements for the year ended December 31, 2019. 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, 2019.

The 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 such terms as “we,” “our” or “us”). All material intercompany balances and transactions have been eliminated in consolidation.

Adoption of New Accounting Standards and Recently Issued Accounting Standards

Recent Issued Accounting Pronouncements: In March 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2020-04, Reference Rate Reform (Topic 848) ("ASU 2020-04"), which provides optional expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by the discontinuation of the London Interbank Offered Rate ("LIBOR") or by another reference rate expected to be discontinued. The amendments are effective for all entities as of March 12, 2020 through December 31, 2022. We are currently evaluating the impacts of the the provisions of ASU 2020-04 on our consolidated financial statements.

In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, an update intended to simplify various aspects related to accounting for income taxes. This guidance removes certain exceptions to the general principles in Topic 740 and clarifies and amends existing guidance to improve consistent application. This accounting standards update will be effective for annual and interim financial statement periods beginning after December 15, 2020, with early adoption permitted. We are currently evaluating the impact of this accounting standards update, but do not expect the adoption to materially impact our consolidated financial statements.

Adoption of New Accounting Standards: In June 2016, the FASB issued ASU 2016-13, Measurement of Credit Losses on Financial Instruments, which requires that an entity measure impairment of certain financial instruments, including trade receivables, based on expected losses rather than incurred losses. We adopted ASU 2016-13 on January 1, 2020. The adoption of this new standard resulted in the recognition of $1 million of incremental bad debt expense in the three months ended March 31, 2020.

Valuation of Goodwill and Indefinite-Lived Intangibles

Valuation of Goodwill and Indefinite-Lived Intangibles: We apply a fair value-based impairment test to the carrying value of goodwill and indefinite-lived intangible assets on an annual basis (as of October 1) and, if certain events or circumstances indicate that an impairment loss may have been incurred, on an interim basis. Our October 2019 quantitative impairment tests for goodwill and indefinite-lived intangible assets indicated there was no impairment as the fair value of each of our reporting units and indefinite-lived intangible assets exceeded carrying value by a significant margin, with the exception of our International reporting unit for which the excess was approximately 20%.

As a result of our reduced forecasts and the significant decline in our market capitalization as a result of the coronavirus disease 2019 (“COVID-19”) pandemic, we qualitatively assessed whether it was more likely than not our goodwill or indefinite-lived intangible assets were impaired as of March 31, 2020. We reviewed our previous forecasts and assumptions based on our current projections that are subject to various risks and uncertainties, including: (1) forecasted revenues, expenses and cash flows, including the duration and extent of impact to our business from the COVID-19 pandemic, (2) current discount rates, (3) the reduction in our market capitalization, and (4) control premiums on observable market conditions.

Based on our qualitative assessment, we concluded that our goodwill and indefinite-lived intangible assets were not impaired as of March 31, 2020. However, we are unable to predict how long current market conditions will persist, what additional measures may be introduced by governments or private parties or what effect any such additional measures may have on our business. To the extent we are unable to conclude in a future period that it is more likely than not our goodwill and indefinite-lived intangible assets are not impaired, we would be required to perform a full quantitative impairment test, the results of which could require recognition of an impairment charge in future periods.