Summary of Significant Accounting Policies (Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Numerator:
Numerator for both basic and diluted EPS attributable to HNI Corporation net income	$ 93,377	$ 89,795	$ 85,577
Denominators:
Denominator for basic EPS weighted- average common shares outstanding (in shares)	43,639,003	43,839,004	44,413,941
Potentially dilutive shares from stock-based compensation plans (shares)	689,000	1,001,000	1,088,000
Denominator for diluted EPS (shares)	44,327,602	44,839,813	45,502,219
Earnings per share - basic (in dollars per share)	$ 2.14	$ 2.05	$ 1.93
Earnings per share - diluted (in dollars per share)	$ 2.11	$ 2.00	$ 1.88
Stock Compensation Plan
Denominators:
Common stock equivalents excluded because their inclusion would be anti-dilutive (in shares)	1,507,870	809,420	416,142