3.26.1 html 77 34 1 false 10 0 false 1 false false R1.htm 995100 - Document - Cover Sheet http://xbrl.sec.gov/dei/role/document/Cover Cover Cover 1 false false R2.htm 995410 - Disclosure - Pay vs Performance Disclosure Sheet http://xbrl.sec.gov/ecd/role/PvpDisclosure Pay vs Performance Disclosure Notes 2 false false R3.htm 995443 - Disclosure - Award Timing Disclosure Sheet http://xbrl.sec.gov/ecd/role/AwardTimingDisclosure Award Timing Disclosure Notes 3 false false R4.htm 995447 - Disclosure - Insider Trading Policies and Procedures Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingPoliciesProc Insider Trading Policies and Procedures Notes 4 false false All Reports Book All Reports hni-20260520.xsd hni-20260520_def.xml ny20067633x2_def14a.htm logo_hni2.jpg ny20019808x999_cross.jpg ny20019808x999_tick.jpg ny20067633x2_abell.jpg ny20067633x2_boardchart.jpg ny20067633x2_bporcellato.jpg ny20067633x2_cebrown.jpg ny20067633x2_ceochart.jpg ny20067633x2_dhalinan.jpg ny20067633x2_dlornger.jpg ny20067633x2_dmroberts.jpg ny20067633x2_hni-footer.jpg ny20067633x2_ibc01.jpg ny20067633x2_ibc02.jpg ny20067633x2_ifc01.jpg ny20067633x2_ifc02.jpg ny20067633x2_ifc03.jpg ny20067633x2_ifc04.jpg ny20067633x2_ifc05x1.jpg ny20067633x2_ifc06.jpg ny20067633x2_ifc07.jpg ny20067633x2_ifc08.jpg ny20067633x2_ifc09.jpg ny20067633x2_ifc10.jpg ny20067633x2_ifc11.jpg ny20067633x2_ifc12.jpg ny20067633x2_ifc13.jpg ny20067633x2_ifc14.jpg ny20067633x2_ifc15.jpg ny20067633x2_ifc16.jpg ny20067633x2_kwilliams.jpg ny20067633x2_kwjones.jpg ny20067633x2_pc01.jpg ny20067633x2_pc02.jpg ny20067633x2_pvpchart1.jpg ny20067633x2_pvpchart2.jpg ny20067633x2_pvpchart3.jpg ny20067633x2_rhartnett.jpg ny20067633x2_sivajee.jpg ny20067633x2_skilltable1.jpg sig_bradford.jpg http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 false false