Basis of Presentation & Description of Business (Policies)	3 Months Ended
	Apr. 28, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation - Consolidation	The accompanying unaudited condensed consolidated financial statements present the results of operations, financial position and cash flows of Core & Main and its subsidiaries, which includes the consolidated financial statements of Holdings and its consolidated subsidiary, Core & Main LP, as the legal entity that conducts the operations of the Company. All intercompany balances and transactions have been eliminated in consolidation. The Company records non-controlling interests related to Partnership Interests held by Management Feeder in Holdings.
Basis of Presentation - Accounting	In management’s opinion, the unaudited condensed consolidated financial information for the interim periods presented include all normal recurring adjustments necessary for a fair statement of the Company's results of operations, financial position and cash flows, which include all disclosures required by accounting principles generally accepted in the United States of America (“U.S. GAAP”). Revenues, expenses, assets and liabilities can vary during each quarter of the year. Therefore, the results and trends in these interim unaudited condensed consolidated financial statements may not be the same as those for the full year. The January 28, 2024 condensed consolidated Balance Sheet was derived from audited financial statements as of that date, but does not include all of the information and footnotes required by U.S. GAAP for complete financial statements. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and the related notes thereto as of and for the fiscal year ended January 28, 2024 included in our 2023 Annual Report on Form 10-K.
Fiscal Year	Fiscal Year The Company’s fiscal year is a 52- or 53-week period ending on the Sunday nearest to January 31st. Quarters within the fiscal year include 13-week periods, unless a fiscal year includes a 53rd week, in which case the fourth quarter of the fiscal year will be a 14-week period. Each of the three months ended April 28, 2024 and three months ended April 30, 2023 included 13 weeks. The current fiscal year ending February 2, 2025 (“fiscal 2024”) will include 53 weeks.
Estimates	Estimates Management has made a number of estimates and assumptions relating to the reporting of certain assets and liabilities, the disclosure of contingent assets and liabilities, and the reported amounts of revenues and expenses in preparing the elements of these financial statements in conformity with U.S. GAAP. Actual results could differ from these estimates.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS Segment Reporting - In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, “Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures” (“ASU 2023-07”). The new guidance expands reportable segment disclosure requirements primarily through enhanced disclosures about significant segment expenses. ASU 2023-07 requires disclosure of (i) significant segment expenses that are regularly provided to the segment’s chief operating decision maker (“CODM”) and included within the segment measure of profit or loss, (ii) an amount and description of its composition for other segment items to reconcile to segment profit or loss, and (iii) the title and position of the Company’s CODM. The ASU does not change how a public entity identifies its operating segments, aggregates them, or applies the quantitative thresholds to determine its reportable segments. ASU 2023-07 is effective for annual periods beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the segment disclosure impact of the amended guidance; however, ASU 2023-07 is not expected to have a material impact on its consolidated financial statements. Income Tax Disclosures - In December 2023, the FASB issued ASU No. 2023-09, “Income Taxes (Topic 740): Improvements to Income Tax Disclosures” (“ASU 2023-09”). The new guidance requires, on an annual basis, disclosure of specific categories in the rate reconciliation and disclosure of income taxes paid disaggregated by jurisdiction. ASU 2023-09 is effective for annual periods beginning after December 15, 2024. The Company is currently evaluating the income tax disclosure impact of the amended guidance; however, ASU 2023-09 is not expected to have a material impact on its consolidated financial statements.