CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Income Statement [Abstract]
Net sales	$ 507,063	$ 625,386	$ 1,393,224	$ 1,630,868
Cost of sales	321,516	387,715	880,754	1,030,993
Gross profit	185,547	237,671	512,470	599,875
Selling and administrative expenses	146,785	176,731	449,933	511,080
Impairment and restructuring charges	0	284	32,661	1,214
Operating income	38,762	60,656	29,876	87,581
Interest expense, net	1,517	2,205	5,271	6,795
Income before income taxes	37,245	58,451	24,605	80,786
Income taxes	6,558	12,375	5,259	17,878
Net income	30,687	46,076	19,346	62,908
Less: Net income (loss) attributable to non-controlling interest	(1)	(2)	(3)	(2)
Net income attributable to HNI Corporation	$ 30,688	$ 46,078	$ 19,349	$ 62,910
Average number of common shares outstanding – basic (in shares)	42,684	42,899	42,651	43,217
Net income attributable to HNI Corporation per common share – basic (in dollars per share)	$ 0.72	$ 1.07	$ 0.45	$ 1.46
Average number of common shares outstanding – diluted (in shares)	43,010	43,186	42,905	43,620
Net income attributable to HNI Corporation per common share – diluted (in dollars per share)	$ 0.71	$ 1.07	$ 0.45	$ 1.44
Foreign currency translation adjustments	$ 923	$ (1,035)	$ 368	$ (406)
Change in unrealized gains (losses) on marketable securities, net of tax	(33)	36	269	252
Change in pension and post-retirement liability, net of tax	0	0	0	(1,185)
Change in derivative financial instruments, net of tax	106	(477)	(2,393)	(2,112)
Other comprehensive income (loss), net of tax	996	(1,476)	(1,756)	(3,451)
Comprehensive income	31,683	44,600	17,590	59,457
Less: Comprehensive income (loss) attributable to non-controlling interest	(1)	(2)	(3)	(2)
Comprehensive income attributable to HNI Corporation	$ 31,684	$ 44,602	$ 17,593	$ 59,459