Earnings Per Share - Schedule of Earnings Per Share Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 02, 2022	Jul. 03, 2021	Jul. 02, 2022	Jul. 03, 2021
Numerator:
Numerator for both basic and diluted EPS attributable to HNI Corporation net income	$ 30.3	$ 17.4	$ 44.5	$ 32.4
Denominators:
Denominator for basic EPS weighted-average common shares outstanding (in shares)	41.8	43.8	42.1	43.5
Potentially dilutive shares from stock-based compensation plans (in shares)	0.6	0.7	0.6	0.5
Denominator for diluted EPS (in shares)	42.4	44.5	42.7	44.0
Earnings per share - basic (in dollars per share)	$ 0.73	$ 0.40	$ 1.06	$ 0.75
Earnings per share - diluted (in dollars per share)	$ 0.72	$ 0.39	$ 1.04	$ 0.74