Consolidated Statement of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Consolidated Statement of Income [Abstract]
Revenues (Note 12)	$ 331,751	$ 335,460	$ 270,029
Costs and Operating Expenses:
Cost of revenues	185,949	190,247	151,604
Selling, general, and administrative expenses	103,101	102,660	89,212
Research and development expenses	5,950	5,717	5,269
Restructuring costs and other expense (income), net (Note 8)	307	(1,874)	(1,005)
Total Costs and Operating Expenses	295,307	296,750	245,080
Operating Income	36,444	38,710	24,949
Interest Income	319	499	214
Interest Expense	(833)	(1,066)	(1,315)
Income from Continuing Operations Before Provision for Income Taxes	35,930	38,143	23,848
Provision for Income Taxes (Note 5)	4,852	4,285	5,198
Income from Continuing Operations	31,078	33,858	18,650
Income (Loss) from Discontinued Operation (net of income tax (expense) benefit of $(451), $1,511, and $164 in 2012, 2011, and 2010, respectively; Note 9)	743	(9)	98
Net Income	31,821	33,849	18,748
Net Income Attributable to Noncontrolling Interest	(198)	(274)	(241)
Net Income Attributable to Kadant	31,623	33,575	18,507
Amounts Attributable to Kadant:
Income from Continuing Operations	30,880	33,584	18,409
Income (Loss) from Discontinued Operation	743	(9)	98
Net Income Attributable to Kadant	$ 31,623	$ 33,575	$ 18,507
Earnings per Share from Continuing Operations Attributable to Kadant (Note 13)
Basic (in dollars per share)	$ 2.70	$ 2.77	$ 1.49
Diluted (in dollars per share)	$ 2.66	$ 2.74	$ 1.48
Earnings per Share Attributable to Kadant (Note 13)
Basic (in dollars per share)	$ 2.76	$ 2.77	$ 1.50
Diluted (in dollars per share)	$ 2.73	$ 2.74	$ 1.48
Weighted Average Shares (Note 13)
Basic (in shares)	11,456	12,124	12,339
Diluted (in shares)	11,590	12,261	12,466