Condensed Consolidated Statement of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Statement of Comprehensive Income [Abstract]
Net Income	$ 12,656	$ 11,065
Other Comprehensive Items:
Foreign currency translation adjustment	(12,574)	(465)
Pension and other post-retirement liability adjustments, net (net of tax of $20 and $8)	50	21
Effect of other post-retirement plan settlement	(119)	0
Deferred loss on cash flow hedges (net of tax of $119 and $104)	(302)	(237)
Net current period other comprehensive items	(12,945)	(681)
Comprehensive (Loss) Income	(289)	10,384
Comprehensive Income Attributable to Noncontrolling Interest	(114)	(132)
Comprehensive (Loss) Income Attributable to Kadant	$ (403)	$ 10,252