Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2025	Jun. 29, 2024	Jun. 28, 2025	Jun. 29, 2024
Income Statement [Abstract]
Net sales	$ 667.1	$ 623.7	$ 1,266.8	$ 1,211.7
Cost of sales	380.9	362.4	742.3	717.5
Gross profit	286.2	261.3	524.6	494.2
Selling and administrative expenses	215.5	205.9	423.1	409.0
Restructuring, impairment, and loss on divestiture	2.5	2.0	8.9	2.1
Operating income	68.2	53.4	92.6	83.1
Interest expense, net	6.1	7.4	11.7	15.1
Income before income taxes	62.0	46.0	80.9	68.0
Income taxes	13.8	10.0	18.8	14.3
Net income	48.3	36.0	62.2	53.7
Less: Net income (loss) attributable to non-controlling interest	0.0	0.0	0.0	0.0
Net income attributable to HNI Corporation	$ 48.2	$ 36.0	$ 62.2	$ 53.7
Average number of common shares outstanding – basic (in shares)	46.2	47.2	46.6	47.1
Net income attributable to HNI Corporation per common share – basic (in dollars per share)	$ 1.04	$ 0.76	$ 1.33	$ 1.14
Average number of common shares outstanding – diluted (in shares)	47.1	48.2	47.6	48.2
Net income attributable to HNI Corporation per common share – diluted (in dollars per share)	$ 1.02	$ 0.75	$ 1.31	$ 1.11
Foreign currency translation adjustments	$ 6.4	$ (0.1)	$ 6.3	$ (0.1)
Change in unrealized gains (losses) on marketable securities, net of tax	0.1	0.0	0.2	0.0
Change in pension and post-retirement liability, net of tax	2.0	0.0	2.0	0.0
Change in derivative financial instruments, net of tax	(0.1)	0.3	(0.6)	1.7
Other comprehensive income (loss), net of tax	8.4	0.3	7.9	1.7
Comprehensive income	56.7	36.3	70.0	55.4
Less: Comprehensive income (loss) attributable to non-controlling interest	0.0	0.0	0.0	0.0
Comprehensive income attributable to HNI Corporation	$ 56.6	$ 36.3	$ 70.0	$ 55.4