CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Income Statement [Abstract]
Net sales	$ 543,614	$ 514,485	$ 1,048,683	$ 992,152
Cost of sales	342,744	329,733	670,894	633,677
Gross profit	200,870	184,752	377,789	358,475
Selling and administrative expenses	172,973	162,684	344,868	326,350
Restructuring and impairment charges	837	419	2,175	2,542
Operating income	27,060	21,649	30,746	29,583
Interest income	89	325	202	396
Interest expense	2,718	1,347	5,055	2,393
Income before income taxes	24,431	20,627	25,893	27,586
Income taxes	5,835	6,771	4,836	8,949
Net income	18,596	13,856	21,057	18,637
Less: Net income (loss) attributable to non-controlling interest	(1)	8	(50)	(48)
Net income attributable to HNI Corporation	$ 18,597	$ 13,848	$ 21,107	$ 18,685
Average number of common shares outstanding – basic (in shares)	43,665,411	44,178,287	43,512,691	44,114,164
Net income attributable to HNI Corporation per common share – basic (in dollars per share)	$ 0.43	$ 0.31	$ 0.49	$ 0.42
Average number of common shares outstanding – diluted (in shares)	44,289,662	45,305,547	44,201,285	45,375,451
Net income attributable to HNI Corporation per common share – diluted (in dollars per share)	$ 0.42	$ 0.31	$ 0.48	$ 0.41
Foreign currency translation adjustments	$ (1,128)	$ 115	$ (1,127)	$ 459
Change in unrealized gains (losses) on marketable securities, net of tax	(13)	19	(92)	37
Change in derivative financial instruments, net of tax	326	(394)	1,353	(129)
Other comprehensive income (loss), net of tax	(815)	(260)	134	367
Comprehensive income	17,781	13,596	21,191	19,004
Less: Comprehensive income (loss) attributable to non-controlling interest	(1)	8	(50)	(48)
Comprehensive income attributable to HNI Corporation	$ 17,782	$ 13,588	$ 21,241	$ 19,052