Earnings per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 28, 2013	Sep. 29, 2012	Sep. 28, 2013	Sep. 29, 2012
Amounts Attributable to Kadant [Abstract]
Income from Continuing Operations	$ 6,461	$ 7,617	$ 17,546	$ 21,277
(Loss) Income from Discontinued Operation	(14)	844	(55)	780
Net Income Attributable to Kadant	$ 6,447	$ 8,461	$ 17,491	$ 22,057
Basic Weighted Average Shares (in shares)	11,153,000	11,341,000	11,165,000	11,523,000
Effect of Stock Options, Restricted Stock Units and Employee Stock Purchase Plan (in shares)	212,000	150,000	156,000	110,000
Diluted Weighted Average Shares (in shares)	11,365,000	11,491,000	11,321,000	11,633,000
Basic Earnings Per Share [Abstract]
Continuing operations (in dollars per share)	$ 0.58	$ 0.67	$ 1.57	$ 1.85
Discontinued operation (in dollars per share)	$ 0.00	$ 0.07	$ 0.00	$ 0.07
Net Income per Basic Share (in dollars per share)	$ 0.58	$ 0.75	$ 1.57	$ 1.91
Diluted Earnings Per Share [Abstract]
Continuing operations (in dollars per share)	$ 0.57	$ 0.66	$ 1.55	$ 1.83
Discontinued operation (in dollars per share)	$ 0.00	$ 0.07	$ 0.00	$ 0.07
Net Income per Diluted Share (in dollars per share)	$ 0.57	$ 0.74	$ 1.55	$ 1.90
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	92,900	164,400	99,000	145,300
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		0	27,200	38,000