Consolidated Statement of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Jan. 03, 2015
Income Statement [Abstract]
Revenues (Note 11)	$ 414,126	$ 390,107	$ 402,127
Costs and Operating Expenses:
Cost of revenues	225,737	209,982	223,754
Selling, general, and administrative expenses	135,753	122,814	129,319
Research and development expenses	7,380	6,677	6,163
Other income and restructuring costs (Note 8)	(317)	515	805
Total Costs and Operating Expenses	368,553	339,988	360,041
Operating Income	45,573	50,119	42,086
Interest Income	269	200	398
Interest Expense	(1,293)	(948)	(966)
Income from Continuing Operations Before Provision for Income Taxes	44,549	49,371	41,518
Provision for Income Taxes (Note 5)	12,083	14,762	12,447
Income from Continuing Operations	32,466	34,609	29,071
Income (Loss) from Discontinued Operation (net of income tax (provision) benefit of $(2), $(43), and $14 in 2016, 2015, and 2014, respectively)	3	74	(23)
Net Income	32,469	34,683	29,048
Net Income Attributable to Noncontrolling Interest	(392)	(294)	(389)
Net Income Attributable to Kadant	32,077	34,389	28,659
Amounts Attributable to Kadant:
Income from Continuing Operations	32,074	34,315	28,682
Income (Loss) from Discontinued Operation	3	74	(23)
Net Income Attributable to Kadant	$ 32,077	$ 34,389	$ 28,659
Earnings per Share from Continuing Operations Attributable to Kadant (Note 12)
Basic (in dollars per share)	$ 2.95	$ 3.16	$ 2.61
Diluted (in dollars per share)	2.88	3.09	2.56
Earnings per Share Attributable to Kadant (Note 12)
Basic (in dollars per share)	2.95	3.16	2.61
Diluted (in dollars per share)	$ 2.88	$ 3.10	$ 2.56
Weighted Average Shares (Note 12)
Basic (in shares)	10,869	10,867	10,988
Diluted (in shares)	11,149	11,094	11,210
Cash Dividends Declared per Common Share (in dollars per share)	$ 0.76	$ 0.68	$ 0.60