Condensed Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2025	Jun. 29, 2024	Jun. 28, 2025	Jun. 29, 2024
Income Statement [Abstract]
Revenue (Notes 1 and 8)	$ 255,267	$ 274,765	$ 494,477	$ 523,740
Costs and Operating Expenses:
Cost of revenue	138,225	152,878	267,105	290,891
Selling, general, and administrative expenses	73,941	70,004	145,162	140,309
Research and development expenses	3,724	3,482	7,247	7,212
Total Costs and Operating Expenses	215,890	226,364	419,514	438,412
Operating Income	39,377	48,401	74,963	85,328
Interest Income	439	368	956	979
Interest Expense	(3,338)	(5,201)	(7,160)	(9,870)
Other Expense, Net	(17)	(2)	(33)	(32)
Income Before Provision for Income Taxes	36,461	43,566	68,726	76,405
Provision for Income Taxes (Note 3)	9,822	11,992	17,650	19,846
Net Income	26,639	31,574	51,076	56,559
Net Income Attributable to Noncontrolling Interests	(480)	(283)	(854)	(579)
Net Income Attributable to Kadant	$ 26,159	$ 31,291	$ 50,222	$ 55,980
Earnings per Share Attributable to Kadant (Note 2)
Basic (in dollars per share)	$ 2.22	$ 2.66	$ 4.27	$ 4.77
Diluted (in dollars per share)	$ 2.22	$ 2.66	$ 4.26	$ 4.76
Weighted Average Shares (Note 2)
Basic (in shares)	11,776	11,743	11,768	11,734
Diluted (in shares)	11,793	11,766	11,784	11,755