Recently Issued Accounting Standards (Policies)	3 Months Ended
Aug. 28, 2021
Accounting Standards Update and Change in Accounting Principle [Abstract]
Basis of Presentation	Basis of Presentation The Condensed Consolidated Financial Statements have been prepared by Herman Miller, Inc. (“the Company”) in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Management believes the disclosures made in this document are adequate with respect to interim reporting requirements. Unless otherwise noted or indicated by the context, all references to "Herman Miller," "MillerKnoll," "Herman Miller Group," "we," "our," "Company" and similar references are to Herman Miller, Inc., its predecessors, and controlled subsidiaries. The accompanying unaudited Condensed Consolidated Financial Statements, taken as a whole, contain all adjustments that are of a normal recurring nature necessary to present fairly the financial position of the Company as of August 28, 2021. Operating results for the three months ended August 28, 2021 are not necessarily indicative of the results that may be expected for the year ending May 28, 2022 ("fiscal 2022"). It is suggested that these Condensed Consolidated Financial Statements be read in conjunction with the financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended May 29, 2021 ("fiscal 2021").
Intercompany Transactions	All intercompany transactions have been eliminated in the Condensed Consolidated Financial Statements. The financial statements of equity method investments are not consolidated.
Segment Reorganization	Segment Reorganization Effective as of May 30, 2021, the beginning of fiscal year 2022, the Company implemented an organizational change that resulted in a change in the reportable segments. The Company has recast historical results to reflect this change. Below is a description of each reportable segment. Intersegment sales are eliminated within each segment, with the exception of sales to and from the Knoll segment, which are presented as intersegment eliminations. •Global Retail – reflects the legacy North America Retail segment and now includes International Retail •Americas Contract ("Americas") – reflects the legacy Herman Miller North America Contract segment combined with Latin America and Design Within Reach Contract •International Contract ("International") – reflects global Contract activity outside the Americas, excluding the international activity of Knoll •Knoll – the Knoll segment includes the global operations associated with the design, manufacture, and sale of furniture products within the Knoll constellation of brands. The acquired Knoll business will initially be reflected as a stand-alone segment.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards On May 30, 2021, the Company adopted ASU No. 2018-14, "Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans." This update eliminates, adds and clarifies certain disclosure requirements for employers that sponsor defined benefit pension or other post-retirement plans. The eliminated disclosures include (a) the amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit costs over the next fiscal year and (b) the effects of a one percentage point change in assumed health care cost trend rates on the net periodic benefit costs and the benefit obligation for post-retirement health care benefits. Additional disclosures include descriptions of significant gains and losses affecting the benefit obligation for the period. The adoption of this guidance did not have a material effect on our consolidated financial statements and additional disclosures will be made in our annual report. On May 30, 2021, the Company adopted ASU 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes." This update removes certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. The update also adds guidance to reduce complexity in certain areas. The adoption of this guidance did not have a material impact on the Company's financial statements. Recently Issued Accounting Standards Not Yet Adopted The Company evaluates all Accounting Standards Updates ("ASUs") issued by the Financial Accounting Standards Board ("FASB") for consideration of their applicability to our consolidated financial statements. We have assessed all ASUs issued but not yet adopted and concluded that those not disclosed are not relevant to the Company or are not expected to have a material impact.
Inventories, net	Inventories are valued at the lower of cost or market and include material, labor, and overhead. Certain inventories within our United States-based manufacturing operations are valued using the last-in, first-out (LIFO) method. Inventories of all other operations are valued using the first-in, first-out (FIFO) method.
Share-Based Compensation	Certain of the Company's equity-based compensation awards contain provisions that allow for continued vesting into retirement. Stock-based awards are considered fully vested for expense attribution purposes when the employee's retention of the award is no longer contingent on providing subsequent service.
Fair Value of Financial Instruments	The cost of securities sold is based on the specific identification method; realized gains and losses resulting from such sales are included in the Condensed Consolidated Statements of Comprehensive Income within "Other expense (income), net".
Marketable Securities	The Company views its equity and fixed income mutual funds as available for use in its current operations. Accordingly, the investments are recorded within Current Assets within the Condensed Consolidated Balance Sheets.
Derivative Instruments and Hedging Activities	Derivative Instruments and Hedging Activities Foreign Currency Forward Contracts The Company transacts business in various foreign currencies and has established a program that primarily utilizes foreign currency forward contracts to reduce the risks associated with the effects of certain foreign currency exposures. Under this program, the Company's strategy is to have increases or decreases in our foreign currency exposures offset by gains or losses on the foreign currency forward contracts to mitigate the risks and volatility associated with foreign currency transaction gains or losses. Foreign currency exposures typically arise from net liability or asset exposures in non-functional currencies on the balance sheets of our foreign subsidiaries. Foreign currency forward contracts generally settle within 30 days and are not used for trading purposes. These forward contracts are not designated as hedging instruments. Accordingly, we record the fair value of these contracts as of the end of the reporting period in the Consolidated Balance Sheets with changes in fair value recorded within the Consolidated Statements of Comprehensive Income. The balance sheet classification for the fair values of these forward contracts is to "Other current assets" for unrealized gains and to "Other accrued liabilities" for unrealized losses. The Consolidated Statements of Comprehensive Income classification for the fair values of these forward contracts is to "Other (income) expense, net", for both realized and unrealized gains and losses. Interest Rate Swaps The Company enters into interest rate swap agreements to manage its exposure to interest rate changes and its overall cost of borrowing. The Company's interest rate swap agreements exchange variable rate interest payments for fixed rate payments over the life of the agreement without the exchange of the underlying notional amounts. The notional amount of the interest rate swap agreements is used to measure interest to be paid or received. The differential paid or received on the interest rate swap agreements is recognized as an adjustment to interest expense. The interest rate swaps were designated as cash flow hedges at inception and the facts and circumstances of the hedged relationships remain consistent with the initial quantitative effectiveness assessment in that the hedged instruments remain an effective accounting hedge as of August 28, 2021. Since a designated derivative meets hedge accounting criteria, the fair value of the hedge is recorded in the Consolidated Statements of Stockholders’ Equity as a component of "Accumulated other comprehensive loss, net of tax." The ineffective portion of the change in fair value of the derivatives is immediately recognized in earnings. The interest rate swap agreements are assessed for hedge effectiveness on a quarterly basis.

Recently Issued Accounting Standards (Policies)

3 Months Ended

Aug. 28, 2021

Accounting Standards Update and Change in Accounting Principle [Abstract]

The Condensed Consolidated Financial Statements have been prepared by Herman Miller, Inc. (“the Company”) in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. Management believes the disclosures made in this document are adequate with respect to interim reporting requirements. Unless otherwise noted or indicated by the context, all references to "Herman Miller," "MillerKnoll," "Herman Miller Group," "we," "our," "Company" and similar references are to Herman Miller, Inc., its predecessors, and controlled subsidiaries.

The accompanying unaudited Condensed Consolidated Financial Statements, taken as a whole, contain all adjustments that are of a normal recurring nature necessary to present fairly the financial position of the Company as of August 28, 2021. Operating results for the three months ended August 28, 2021 are not necessarily indicative of the results that may be expected for the year ending May 28, 2022 ("fiscal 2022"). It is suggested that these Condensed Consolidated Financial Statements be read in conjunction with the financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the year ended May 29, 2021 ("fiscal 2021").

Intercompany Transactions

All intercompany transactions have been eliminated in the Condensed Consolidated Financial Statements. The financial statements of equity method investments are not consolidated.

Segment Reorganization

Effective as of May 30, 2021, the beginning of fiscal year 2022, the Company implemented an organizational change that resulted in a change in the reportable segments. The Company has recast historical results to reflect this change. Below is a description of each reportable segment. Intersegment sales are eliminated within each segment, with the exception of sales to and from the Knoll segment, which are presented as intersegment eliminations.

•Global Retail – reflects the legacy North America Retail segment and now includes International Retail

•Americas Contract ("Americas") – reflects the legacy Herman Miller North America Contract segment combined with Latin America and Design Within Reach Contract

•International Contract ("International") – reflects global Contract activity outside the Americas, excluding the international activity of Knoll

•Knoll – the Knoll segment includes the global operations associated with the design, manufacture, and sale of furniture products within the Knoll constellation of brands. The acquired Knoll business will initially be reflected as a stand-alone segment.

Recently Adopted Accounting Standards

On May 30, 2021, the Company adopted ASU No. 2018-14, "Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20): Disclosure Framework - Changes to the Disclosure Requirements for Defined Benefit Plans." This update eliminates, adds and clarifies certain disclosure requirements for employers that sponsor defined benefit pension or other post-retirement plans. The eliminated disclosures include (a) the amounts in accumulated other comprehensive income expected to be recognized in net periodic benefit costs over the next fiscal year and (b) the effects of a one percentage point change in assumed health care cost trend rates on the net periodic benefit costs and the benefit obligation for post-retirement health care benefits. Additional disclosures include descriptions of significant gains and losses affecting the benefit obligation for the period. The adoption of this guidance did not have a material effect on our consolidated financial statements and additional disclosures will be made in our annual report.

On May 30, 2021, the Company adopted ASU 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes." This update removes certain exceptions for recognizing deferred taxes for investments, performing intra-period allocation and calculating income taxes in interim periods. The update also adds guidance to reduce complexity in certain areas. The adoption of this guidance did not have a material impact on the Company's financial statements.

Recently Issued Accounting Standards Not Yet Adopted

The Company evaluates all Accounting Standards Updates ("ASUs") issued by the Financial Accounting Standards Board ("FASB") for consideration of their applicability to our consolidated financial statements. We have assessed all ASUs issued but not yet adopted and concluded that those not disclosed are not relevant to the Company or are not expected to have a material impact.

Inventories, net

Inventories are valued at the lower of cost or market and include material, labor, and overhead. Certain inventories within our United States-based manufacturing operations are valued using the last-in, first-out (LIFO) method. Inventories of all other operations are valued using the first-in, first-out (FIFO) method.

Share-Based Compensation

Certain of the Company's equity-based compensation awards contain provisions that allow for continued vesting into retirement. Stock-based awards are considered fully vested for expense attribution purposes when the employee's retention of the award is no longer contingent on providing subsequent service.

Fair Value of Financial Instruments

The cost of securities sold is based on the specific identification method; realized gains and losses resulting from such sales are included in the Condensed Consolidated Statements of Comprehensive Income within "Other expense (income), net".

Marketable Securities

The Company views its equity and fixed income mutual funds as available for use in its current operations. Accordingly, the investments are recorded within Current Assets within the Condensed Consolidated Balance Sheets.

Derivative Instruments and Hedging Activities

Foreign Currency Forward Contracts

The Company transacts business in various foreign currencies and has established a program that primarily utilizes foreign currency forward contracts to reduce the risks associated with the effects of certain foreign currency exposures. Under this program, the Company's strategy is to have increases or decreases in our foreign currency exposures offset by gains or losses on the foreign currency forward contracts to mitigate the risks and volatility associated with foreign currency transaction gains or losses. Foreign currency exposures typically arise from net liability or asset exposures in non-functional currencies on the balance sheets of our foreign subsidiaries. Foreign currency forward contracts generally settle within 30 days and are not used for trading purposes.

These forward contracts are not designated as hedging instruments. Accordingly, we record the fair value of these contracts as of the end of the reporting period in the Consolidated Balance Sheets with changes in fair value recorded within the Consolidated Statements of Comprehensive Income. The balance sheet classification for the fair values of these forward contracts is to "Other current assets" for unrealized gains and to "Other accrued liabilities" for unrealized losses. The Consolidated Statements of Comprehensive Income classification for the fair values of these forward contracts is to "Other (income) expense, net", for both realized and unrealized gains and losses.

Interest Rate Swaps

The Company enters into interest rate swap agreements to manage its exposure to interest rate changes and its overall cost of borrowing. The Company's interest rate swap agreements exchange variable rate interest payments for fixed rate payments over the life of the agreement without the exchange of the underlying notional amounts. The notional amount of the interest rate swap agreements is used to measure interest to be paid or received. The differential paid or received on the interest rate swap agreements is recognized as an adjustment to interest expense.

The interest rate swaps were designated as cash flow hedges at inception and the facts and circumstances of the hedged relationships remain consistent with the initial quantitative effectiveness assessment in that the hedged instruments remain an effective accounting hedge as of August 28, 2021. Since a designated derivative meets hedge accounting criteria, the fair value of the hedge is recorded in the Consolidated Statements of Stockholders’ Equity as a component of "Accumulated other comprehensive loss, net of tax." The ineffective portion of the change in fair value of the derivatives is immediately recognized in earnings. The interest rate swap agreements are assessed for hedge effectiveness on a quarterly basis.