Product Warranties - Schedule of Activity Associated with Warranty Obligations (Details) - USD ($) $ in Millions	9 Months Ended
Sep. 27, 2025	Sep. 28, 2024
Product Warranty Accrual [Roll Forward]
Balance at beginning of period	$ 17.5	$ 18.0
Accruals included in divestiture	(0.4)	0.0
Accruals for warranties issued	10.6	10.1
Settlements and other	(9.6)	(10.1)
Balance at end of period	$ 18.1	$ 18.0

Standard Product Warranty Accrual, Decrease From Business Divestiture

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Standard Product Warranty Accrual, Settlements, Increase (Decrease)

+ References

No definition available.

+ Details

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Namespace Prefix:	hni_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount as of the balance sheet date of the aggregate standard product warranty liability. Does not include the balance for the extended product warranty liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-8

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 460
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (c)(5)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482425/460-10-50-8

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Amount of increase in the standard product warranty accrual from warranties issued. Excludes extended product warranties.

+ References

+ Details

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Period Type:	duration