Significant Accounting Policies (Policies)	6 Months Ended
Jun. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation: The interim consolidated financial statements are unaudited but, in the opinion of management, reflect all adjustments necessary for a fair statement of the Company’s consolidated financial position, results of operations and cash flows for the periods presented. These adjustments consist of normal, recurring items. The results of operations for any interim period are not necessarily indicative of results for the full year. The interim consolidated financial statements and notes are presented as permitted by the requirements for Quarterly Reports on Form 10-Q. This Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes included in its Annual Report on Form 10-K.
New Accounting Pronouncements	New Accounting Pronouncements: Refer to Note 1 to the Consolidated Financial Statements in 3M's 2023 Annual Report on Form 10-K for a discussion of applicable standards issued and not yet adopted by 3M. Relevant New Standards Issued Subsequent to Most Recent Annual Report In March 2024, the SEC adopted rules under SEC Release No. 33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors, which require a registrant to disclose information in annual reports and registration statements about climate-related risks that are reasonably likely to have a material impact on its business, results of operations, or financial condition. The information would include disclosure of a registrant's greenhouse gas emissions. In addition, certain disclosures related to severe weather events and other natural conditions will be required in a registrant’s audited financial statements. Annual disclosure requirements would be effective for 3M as early as the fiscal year beginning January 1, 2025. However, in April 2024, the SEC voluntarily stayed the final rules pending certain legal challenges. The Company is evaluating the impact of these rules on its disclosures.
Earnings (Loss) Per Share	The difference in the weighted average 3M shares outstanding for calculating basic and diluted earnings per share attributable to 3M common shareholders is the result of the dilution associated with the Company’s stock-based compensation plans. Certain awards outstanding under these stock-based compensation plans were not included in the computation of diluted earnings per share attributable to 3M common shareholders because they would have had an anti-dilutive effect of 33.1 million and 32.9 million average options for the three and six months ended June 30, 2024, respectively, and 36.9 million and 36.5 million average options for the three and six months ended June 30, 2023, respectively. In periods of net losses, these anti-dilutive effects include all weighted option shares outstanding and weighted average shares is the same for the calculations of both basic and diluted loss per share.
Legal Proceedings	Process for Disclosure and Recording of Liabilities Related to Legal Proceedings: Many lawsuits and claims involve highly complex issues relating to causation, scientific evidence, and alleged actual damages, all of which are otherwise subject to substantial uncertainties. Assessments of lawsuits and claims can involve a series of complex judgments about future events and can rely heavily on estimates and assumptions. The categories of legal proceedings in which the Company is involved may include multiple lawsuits and claims, may be spread across multiple jurisdictions and courts which may handle the lawsuits and claims differently, may involve numerous and different types of plaintiffs, raising claims and legal theories based on specific allegations that may not apply to other matters, and may seek substantial compensatory and, in some cases, punitive, damages. These and other factors contribute to the complexity of these lawsuits and claims and make it difficult for the Company to predict outcomes and make reasonable estimates of any resulting losses. The Company's ability to predict outcomes and make reasonable estimates of potential losses is further influenced by the fact that a resolution of one or more matters within a category of legal proceedings may impact the resolution of other matters in that category in terms of timing, amount of liability, or both. When making determinations about recording liabilities related to legal proceedings, the Company complies with the requirements of ASC 450, Contingencies, and related guidance, and records liabilities in those instances where it can reasonably estimate the amount of the loss and when the loss is probable. Where the reasonable estimate of the probable loss is a range, the Company records as an accrual in its financial statements the most likely estimate of the loss, or the low end of the range if there is no one best estimate. The Company either discloses the amount of a possible loss or range of loss in excess of established accruals if estimable, or states that such an estimate cannot be made. The Company discloses significant legal proceedings even where liability is not probable or the amount of the liability is not estimable, or both, if the Company believes there is at least a reasonable possibility that a loss may be incurred. Based on experience and developments, the Company reexamines its estimates of probable liabilities and associated expenses and receivables each period, and whether a loss previously determined to not be reasonably estimable and/or not probable is now able to be reasonably estimated or has become probable. Where appropriate, the Company makes additions to or adjustments of its reasonably estimated losses and/or accruals. As a result, the current accruals and/or estimates of loss and the estimates of the potential impact on the Company’s consolidated financial position, results of operations and cash flows for the legal proceedings and claims pending against the Company will likely change over time. Because litigation is subject to inherent uncertainties, and unfavorable rulings or developments could occur, the Company may ultimately incur charges substantially in excess of presently recorded liabilities, including with respect to matters for which no accruals are currently recorded because losses are not currently probable and reasonably estimable. Many of the matters described herein are at varying stages, seek an indeterminate amount of damages or seek damages in amounts that the Company believes are not indicative of the ultimate losses that may be incurred. It is not uncommon for claims to be resolved over many years. As a matter progresses, the Company may receive information, through plaintiff demands, through discovery, in the form of reports of purported experts, or in the context of settlement or mediation discussions that purport to quantify an amount of alleged damages, but with which the Company may not agree. Such information may or may not lead the Company to determine that it is able to make a reasonable estimate as to a probable loss or range of loss in connection with a matter. However, even when a loss or range of loss is not probable and reasonably estimable, developments in, or the ultimate resolution of, a matter could be material to the Company and could have a material adverse effect on the Company, its consolidated financial position, results of operations and cash flows. In addition, future adverse rulings or developments, or settlements in, one or more matters could result in future changes to determinations of probable and reasonably estimable losses in other matters. Process for Disclosure and Recording of Insurance Receivables Related to Legal Proceedings: The Company estimates insurance receivables based on an analysis of the terms of its numerous policies, including their exclusions, pertinent case law interpreting comparable policies, its experience with similar claims, and assessment of the nature of the claim and remaining coverage, and records an amount it has concluded is recognizable and expects to receive in light of the loss recovery and/or gain contingency models under ASC 450, ASC 610-30, and related guidance. For those insured legal proceedings where the Company has recorded an accrued liability in its financial statements, the Company also records receivables for the amount of insurance that it concludes as recognizable from the Company’s insurance program. For those insured matters where the Company has not recorded an accrued liability because the liability is not probable or the amount of the liability is not estimable, or both, but where the Company has incurred an expense in defending itself, the Company records receivables for the amount of insurance that it concludes as recognizable for the expense incurred.
Business Segments	3M’s businesses are organized, managed and internally grouped into segments based on differences in markets, products, technologies and services. 3M manages its operations in three business segments: Safety and Industrial; Transportation and Electronics; and Consumer. 3M’s three business segments bring together common or related 3M technologies, enhancing the development of innovative products and services and providing for efficient sharing of business resources. On April 1, 2024, 3M completed the previously announced separation of its Health Care business as a separate public company, Solventum (see Note 2 for additional information). 3M is an integrated enterprise characterized by substantial intersegment cooperation, cost allocations and inventory transfers. Therefore, management does not represent that these segments, if operated independently, would report the operating income information shown. 3M discloses business segment operating income (loss) as its measure of segment profit/loss, reconciled to both total 3M operating income (loss) and income before taxes. Business segment operating income (loss) excludes certain expenses and income that are not allocated to business segments (as described below in “Corporate and Unallocated and Other”). 3M made certain changes to the composition of segment information reviewed by 3M's chief operating decision maker (CODM) effective in the second quarter of 2024 largely as a result of the separation of Solventum and changes within its business segments effective in the first quarter of 2024. Accordingly, information provided herein reflects the impact of these changes for all applicable periods presented. Effective in the second quarter of 2024, this change included the following: Elimination of former Health Care business segment •The former Health Care business segment was eliminated in the second quarter of 2024 in connection with the separation of Solventum and reflection of its historical net income and applicable assets and liabilities included in the Separation as discontinued operations within 3M's financial statements. Addition of ‘Other’ and update to ‘Corporate and Unallocated’ •3M added the “Other” category of information as a result of the Separation. It principally reflects activity associated with: ◦Transition arrangement agreements (e.g. fees charged by 3M, net of underlying costs) related to divested businesses, including those related to the Separation, as well as other applicable divestitures. ◦Operations of businesses of the former Health Care segment divested prior to the Separation and therefore not reflected as discontinued operations within 3M's financial statements, along with limited-duration supply agreements with those previous divestitures. •Activity included in 3M’s existing “Corporate and Unallocated” was updated primarily to additionally reflect: ◦Removal of costs related to separating and divesting Solventum that were eligible to be part of discontinued operations. ◦Commercial activity with Solventum post-Separation and certain operations of the former Health Care business segment retained by 3M. ◦Costs previously allocated to Solventum prior to the Separation that were not eligible to be part of discontinued operations other than those beginning in the first quarter of 2024 included in “Other” associated with transition arrangement activity for which 3M began to charge fees in April 2024. Corporate and Unallocated and Other: Outside of 3M's operating segments, 3M has Corporate and Unallocated and Other which are not reportable business segments as they do not meet the segment reporting criteria. Because Corporate and Unallocated and Other includes a variety of miscellaneous items, it is subject to fluctuation on a quarterly and annual basis. •Corporate and Unallocated operating income (loss) includes “corporate special items” and “other corporate expense-net”. ◦Corporate special items include net costs for significant litigation impacting operating income (loss) associated with PFAS-related other environmental and Combat Arms Earplugs matters. In addition, during the voluntary chapter 11 bankruptcy period (which began in July 2022 and ended in June 2023—see Note 17), costs associated with the Aearo portion of respirator mask/asbestos matters were also included in corporate special items. Prior to the bankruptcy, costs associated with Combat Arms Earplugs matters were not included in the Corporate net costs for significant litigation special item, instead being reflected in the Safety and Industrial business segment. Corporate special items for the periods presented also include divestiture costs and Russia exit costs/ benefits. Divestiture costs include costs that were not eligible to be part of discontinued operations related to separating and divesting substantially an entire business segment of 3M following public announcement of its intended divestiture. ◦Other corporate expense-net includes certain enterprise and governance activities resulting in unallocated corporate costs and other activity and net costs that 3M may choose not to allocate directly to its business segments. Other corporate expense-net also includes costs previously allocated to Solventum prior to the Separation that were not eligible to be part of discontinued operations, commercial activity with Solventum post-Separation, and certain operations of the former Health Care business segment retained by 3M. •Other principally reflects activity associated with: ◦Operations of businesses of the former Health Care segment divested prior to the Separation and therefore not reflected as discontinued operations within 3M's financial statements, along with limited-duration supply agreements with those previous divestitures. ◦Transition arrangement agreements (e.g. fees charged by 3M, net of underlying costs) related to divested businesses, including those related to the Separation, as well as other applicable divestitures.

Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2024

Basis of Presentation: The interim consolidated financial statements are unaudited but, in the opinion of management, reflect all adjustments necessary for a fair statement of the Company’s consolidated financial position, results of operations and cash flows for the periods presented. These adjustments consist of normal, recurring items. The results of operations for any interim period are not necessarily indicative of results for the full year. The interim consolidated financial statements and notes are presented as permitted by the requirements for Quarterly Reports on Form 10-Q. This Quarterly Report on Form 10-Q should be read in conjunction with the Company’s consolidated financial statements and notes included in its Annual Report on Form 10-K.

New Accounting Pronouncements

New Accounting Pronouncements: Refer to Note 1 to the Consolidated Financial Statements in 3M's 2023 Annual Report on Form 10-K for a discussion of applicable standards issued and not yet adopted by 3M.

Relevant New Standards Issued Subsequent to Most Recent Annual Report

In March 2024, the SEC adopted rules under SEC Release No. 33-11275, The Enhancement and Standardization of Climate-Related Disclosures for Investors, which require a registrant to disclose information in annual reports and registration statements about climate-related risks that are reasonably likely to have a material impact on its business, results of operations, or financial condition. The information would include disclosure of a registrant's greenhouse gas emissions. In addition, certain disclosures related to severe weather events and other natural conditions will be required in a registrant’s audited financial statements. Annual disclosure requirements would be effective for 3M as early as the fiscal year beginning January 1, 2025. However, in April 2024, the SEC voluntarily stayed the final rules pending certain legal challenges. The Company is evaluating the impact of these rules on its disclosures.

Earnings (Loss) Per Share

The difference in the weighted average 3M shares outstanding for calculating basic and diluted earnings per share attributable to 3M common shareholders is the result of the dilution associated with the Company’s stock-based compensation plans. Certain awards outstanding under these stock-based compensation plans were not included in the computation of diluted earnings per share attributable to 3M common shareholders because they would have had an anti-dilutive effect of 33.1 million and 32.9 million average options for the three and six months ended June 30, 2024, respectively, and 36.9 million and 36.5 million average options for the three and six months ended June 30, 2023, respectively. In periods of net losses, these anti-dilutive effects include all weighted option shares outstanding and weighted average shares is the same for the calculations of both basic and diluted loss per share.

Legal Proceedings

Process for Disclosure and Recording of Liabilities Related to Legal Proceedings: Many lawsuits and claims involve highly complex issues relating to causation, scientific evidence, and alleged actual damages, all of which are otherwise subject to substantial uncertainties. Assessments of lawsuits and claims can involve a series of complex judgments about future events and can rely heavily on estimates and assumptions. The categories of legal proceedings in which the Company is involved may include multiple lawsuits and claims, may be spread across multiple jurisdictions and courts which may handle the lawsuits and claims differently, may involve numerous and different types of plaintiffs, raising claims and legal theories based on specific allegations that may not apply to other matters, and may seek substantial compensatory and, in some cases, punitive, damages. These and other factors contribute to the complexity of these lawsuits and claims and make it difficult for the Company to predict outcomes and make reasonable estimates of any resulting losses. The Company's ability to predict outcomes and make reasonable estimates of potential losses is further influenced by the fact that a resolution of one or more matters within a category of legal proceedings may impact the resolution of other matters in that category in terms of timing, amount of liability, or both.

When making determinations about recording liabilities related to legal proceedings, the Company complies with the requirements of ASC 450, Contingencies, and related guidance, and records liabilities in those instances where it can reasonably estimate the amount of the loss and when the loss is probable. Where the reasonable estimate of the probable loss is a range, the Company records as an accrual in its financial statements the most likely estimate of the loss, or the low end of the range if there is no one best estimate. The Company either discloses the amount of a possible loss or range of loss in excess of established accruals if estimable, or states that such an estimate cannot be made. The Company discloses significant legal proceedings even where liability is not probable or the amount of the liability is not estimable, or both, if the Company believes there is at least a reasonable possibility that a loss may be incurred. Based on experience and developments, the Company reexamines its estimates of probable liabilities and associated expenses and receivables each period, and whether a loss previously determined to not be reasonably estimable and/or not probable is now able to be reasonably estimated or has become probable. Where appropriate, the Company makes additions to or adjustments of its reasonably estimated losses and/or accruals. As a result, the current accruals and/or estimates of loss and the estimates of the potential impact on the Company’s consolidated financial position, results of operations and cash flows for the legal proceedings and claims pending against the Company will likely change over time.

Because litigation is subject to inherent uncertainties, and unfavorable rulings or developments could occur, the Company may ultimately incur charges substantially in excess of presently recorded liabilities, including with respect to matters for which no accruals are currently recorded because losses are not currently probable and reasonably estimable. Many of the matters described herein are at varying stages, seek an indeterminate amount of damages or seek damages in amounts that the Company believes are not indicative of the ultimate losses that may be incurred. It is not uncommon for claims to be resolved over many years. As a matter progresses, the Company may receive information, through plaintiff demands, through discovery, in the form of reports of purported experts, or in the context of settlement or mediation discussions that purport to quantify an amount of alleged damages, but with which the Company may not agree. Such information may or may not lead the Company to determine that it is able to make a reasonable estimate as to a probable loss or range of loss in connection with a matter. However, even when a loss or range of loss is not probable and reasonably estimable, developments in, or the ultimate resolution of, a matter could be material to the Company and could have a material adverse effect on the Company, its consolidated financial position, results of operations and cash flows. In addition, future adverse rulings or developments, or settlements in, one or more matters could result in future changes to determinations of probable and reasonably estimable losses in other matters.

Process for Disclosure and Recording of Insurance Receivables Related to Legal Proceedings: The Company estimates insurance receivables based on an analysis of the terms of its numerous policies, including their exclusions, pertinent case law interpreting comparable policies, its experience with similar claims, and assessment of the nature of the claim and remaining coverage, and records an amount it has concluded is recognizable and expects to receive in light of the loss recovery and/or gain contingency models under ASC 450, ASC 610-30, and related guidance. For those insured legal proceedings where the Company has recorded an accrued liability in its financial statements, the Company also records receivables for the amount of insurance that it concludes as recognizable from the Company’s insurance program. For those insured matters where the Company has not recorded an accrued liability because the liability is not probable or the amount of the liability is not estimable, or both, but where the Company has incurred an expense in defending itself, the Company records receivables for the amount of insurance that it concludes as recognizable for the expense incurred.

Business Segments

3M’s businesses are organized, managed and internally grouped into segments based on differences in markets, products, technologies and services. 3M manages its operations in three business segments: Safety and Industrial; Transportation and Electronics; and Consumer. 3M’s three business segments bring together common or related 3M technologies, enhancing the development of innovative products and services and providing for efficient sharing of business resources. On April 1, 2024, 3M completed the previously announced separation of its Health Care business as a separate public company, Solventum (see Note 2 for additional information). 3M is an integrated enterprise characterized by substantial intersegment cooperation, cost allocations and inventory transfers. Therefore, management does not represent that these segments, if operated independently, would report the operating income information shown.

3M discloses business segment operating income (loss) as its measure of segment profit/loss, reconciled to both total 3M operating income (loss) and income before taxes. Business segment operating income (loss) excludes certain expenses and income that are not allocated to business segments (as described below in “Corporate and Unallocated and Other”).

3M made certain changes to the composition of segment information reviewed by 3M's chief operating decision maker (CODM) effective in the second quarter of 2024 largely as a result of the separation of Solventum and changes within its business segments effective in the first quarter of 2024. Accordingly, information provided herein reflects the impact of these changes for all applicable periods presented.

Effective in the second quarter of 2024, this change included the following:

Elimination of former Health Care business segment

•The former Health Care business segment was eliminated in the second quarter of 2024 in connection with the separation of Solventum and reflection of its historical net income and applicable assets and liabilities included in the Separation as discontinued operations within 3M's financial statements.

Addition of ‘Other’ and update to ‘Corporate and Unallocated’

•3M added the “Other” category of information as a result of the Separation. It principally reflects activity associated with:

◦Transition arrangement agreements (e.g. fees charged by 3M, net of underlying costs) related to divested businesses, including those related to the Separation, as well as other applicable divestitures.

◦Operations of businesses of the former Health Care segment divested prior to the Separation and therefore not reflected as discontinued operations within 3M's financial statements, along with limited-duration supply agreements with those previous divestitures.

•Activity included in 3M’s existing “Corporate and Unallocated” was updated primarily to additionally reflect:

◦Removal of costs related to separating and divesting Solventum that were eligible to be part of discontinued operations.

◦Commercial activity with Solventum post-Separation and certain operations of the former Health Care business segment retained by 3M.

◦Costs previously allocated to Solventum prior to the Separation that were not eligible to be part of discontinued operations other than those beginning in the first quarter of 2024 included in “Other” associated with transition arrangement activity for which 3M began to charge fees in April 2024.

Corporate and Unallocated and Other: Outside of 3M's operating segments, 3M has Corporate and Unallocated and Other which are not reportable business segments as they do not meet the segment reporting criteria. Because Corporate and Unallocated and Other includes a variety of miscellaneous items, it is subject to fluctuation on a quarterly and annual basis.

•Corporate and Unallocated operating income (loss) includes “corporate special items” and “other corporate expense-net”.

◦Corporate special items include net costs for significant litigation impacting operating income (loss) associated with PFAS-related other environmental and Combat Arms Earplugs matters. In addition, during the voluntary chapter 11 bankruptcy period (which began in July 2022 and ended in June 2023—see Note 17), costs associated with the Aearo portion of respirator mask/asbestos matters were also included in corporate special items. Prior to the bankruptcy, costs associated with Combat Arms Earplugs matters were not included in the Corporate net costs for significant litigation special item, instead being reflected in the Safety and Industrial business segment. Corporate special items for the periods presented also include divestiture costs and Russia exit costs/ benefits. Divestiture costs include costs that were not eligible to be part of discontinued operations related to separating and divesting substantially an entire business segment of 3M following public announcement of its intended divestiture.

◦Other corporate expense-net includes certain enterprise and governance activities resulting in unallocated corporate costs and other activity and net costs that 3M may choose not to allocate directly to its business segments. Other corporate expense-net also includes costs previously allocated to Solventum prior to the Separation that were not eligible to be part of discontinued operations, commercial activity with Solventum post-Separation, and certain operations of the former Health Care business segment retained by 3M.

•Other principally reflects activity associated with: