Earnings per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Amounts Attributable to Kadant [Abstract]
Income from Continuing Operations	$ 5,313	$ 7,114
Loss from Discontinued Operation	(29)	(61)
Net Income Attributable to Kadant	$ 5,284	$ 7,053
Basic Weighted Average Shares (in shares)	11,163,000	11,653,000
Effect of Stock Options, Restricted Stock Units and Employee Stock Purchase Plan (in shares)	104,000	76,000
Diluted Weighted Average Shares (in shares)	11,267,000	11,729,000
Basic Earnings Per Share [Abstract]
Continuing operations (in dollars per share)	$ 0.48	$ 0.61
Discontinued operation (in dollars per share)	$ 0	$ (0.01)
Net Income per Basic Share (in dollars per share)	$ 0.47	$ 0.61
Diluted Earnings Per Share [Abstract]
Continuing operations (in dollars per share)	$ 0.47	$ 0.61
Discontinued operation (in dollars per share)	$ 0	$ (0.01)
Net Income per Diluted Share (in dollars per share)	$ 0.47	$ 0.60
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)	111,000	107,000
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)	81,000	112,000