Condensed Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 29, 2024	Jul. 01, 2023	Jun. 29, 2024	Jul. 01, 2023
Income Statement [Abstract]
Net sales	$ 623.7	$ 563.5	$ 1,211.7	$ 1,042.5
Cost of sales	362.4	347.9	717.5	652.7
Gross profit	261.3	215.5	494.2	389.8
Selling and administrative expenses	205.9	211.0	409.0	378.9
Restructuring and impairment charges	2.0	8.1	2.1	8.1
Operating income (loss)	53.4	(3.6)	83.1	2.9
Interest expense, net	7.4	5.5	15.1	8.2
Income (loss) before income taxes	46.0	(9.0)	68.0	(5.3)
Income tax expense	10.0	3.8	14.3	6.0
Net income (loss)	36.0	(12.8)	53.7	(11.3)
Less: Net income (loss) attributable to non-controlling interest	0.0	0.0	0.0	0.0
Net income (loss) attributable to HNI Corporation	$ 36.0	$ (12.8)	$ 53.7	$ (11.3)
Average number of common shares outstanding – basic (in shares)	47.2	43.3	47.1	42.4
Net income (loss) attributable to HNI Corporation per common share – basic (in dollars per share)	$ 0.76	$ (0.30)	$ 1.14	$ (0.27)
Average number of common shares outstanding – diluted (in shares)	48.2	43.3	48.2	42.4
Net income (loss) attributable to HNI Corporation per common share – diluted (in dollars per share)	$ 0.75	$ (0.30)	$ 1.11	$ (0.27)
Foreign currency translation adjustments	$ (0.1)	$ 0.0	$ (0.1)	$ 0.0
Change in unrealized gains (losses) on marketable securities, net of tax	0.0	(0.1)	0.0	0.1
Change in derivative financial instruments, net of tax	0.3	0.0	1.7	(0.1)
Other comprehensive income (loss), net of tax	0.3	(0.1)	1.7	0.0
Comprehensive income (loss)	36.3	(12.9)	55.4	(11.2)
Less: Comprehensive income (loss) attributable to non-controlling interest	0.0	0.0	0.0	0.0
Comprehensive income (loss) attributable to HNI Corporation	$ 36.3	$ (12.9)	$ 55.4	$ (11.2)