| Cover Page Document | Jan. 04, 2021 |
| Cover page. [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | May 10, 2021 |
| Entity Registrant Name | HNI Corporation |
| Entity Incorporation, State or Country Code | IA |
| Entity File Number | 1-14225 |
| Entity Tax Identification Number | 42-0617510 |
| Entity Address, Address Line One | 600 East Second Street |
| Entity Address, Address Line Two | P.O. Box 1109 |
| Entity Address, City or Town | Muscatine |
| Entity Address, State or Province | IA |
| Entity Address, Postal Zip Code | 52761-0071 |
| City Area Code | 563 |
| Local Phone Number | 272-7400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | HNI |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0000048287 |
| Amendment Flag | false |
| Current Fiscal Year End Date | --01-01 |
