Earnings per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 27, 2014	Sep. 28, 2013	Sep. 27, 2014	Sep. 28, 2013
Amounts Attributable to Kadant [Abstract]
Income from Continuing Operations	$ 6,651	$ 6,461	$ 19,576	$ 17,546
Loss from Discontinued Operation	(4)	(14)	(18)	(55)
Net Income Attributable to Kadant	$ 6,647	$ 6,447	$ 19,558	$ 17,491
Basic Weighted Average Shares (in shares)	10,898	11,153	11,026	11,165
Effect of Stock Options, Restricted Stock Units and Employee Stock Purchase Plan (in shares)	235	212	205	156
Diluted Weighted Average Shares (in shares)	11,133	11,365	11,231	11,321
Basic Earnings Per Share [Abstract]
Continuing operations (in dollars per share)	$ 0.61	$ 0.58	$ 1.78	$ 1.57
Discontinued operation (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Net Income per Basic Share (in dollars per share)	$ 0.61	$ 0.58	$ 1.77	$ 1.57
Diluted Earnings Per Share [Abstract]
Continuing operations (in dollars per share)	$ 0.60	$ 0.57	$ 1.74	$ 1.55
Discontinued operation (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Net Income per Diluted Share (in dollars per share)	$ 0.60	$ 0.57	$ 1.74	$ 1.55
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)		93		99
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	6		44	27

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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