Condensed Consolidated Statement of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net Income	$ 18,979	$ 13,410	$ 42,478	$ 30,675
Other Comprehensive Items:
Foreign currency translation adjustment	(1,121)	7,740	(11,561)	21,427
Pension and other post-retirement liability adjustments (net of tax provision of $46, $26, $155 and $86)	143	(11)	472	152
Deferred gain on cash flow hedges (net of tax provision (benefit) of $35, $28, ($12) and $44)	100	58	20	92
Other Comprehensive Items	(878)	7,787	(11,069)	21,671
Comprehensive Income	18,101	21,197	31,409	52,346
Comprehensive Income Attributable to Noncontrolling Interest	(191)	(193)	(430)	(574)
Comprehensive Income Attributable to Kadant	$ 17,910	$ 21,004	$ 30,979	$ 51,772