Condensed Consolidated Statement of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2023	Oct. 01, 2022	Sep. 30, 2023	Oct. 01, 2022
Income Statement [Abstract]
Revenue (Notes 1 and 10)	$ 244,182	$ 224,510	$ 718,993	$ 672,639
Costs and Operating Expenses:
Cost of revenue	138,456	129,154	404,671	383,034
Selling, general, and administrative expenses	57,889	53,153	176,441	167,640
Research and development expenses	3,324	3,245	10,102	9,574
Gain on sale and other costs, net (Note 2)	969	72	1,043	(19,936)
Total Costs and Operating Expenses	200,638	185,624	592,257	540,312
Operating Income	43,544	38,886	126,736	132,327
Interest Income	438	271	1,053	650
Interest Expense	(2,107)	(1,721)	(6,722)	(4,321)
Other Expense, Net	(20)	(19)	(62)	(60)
Income Before Provision for Income Taxes	41,855	37,417	121,005	128,596
Provision for Income Taxes (Note 4)	10,816	9,746	31,761	33,075
Net Income	31,039	27,671	89,244	95,521
Net Income Attributable to Noncontrolling Interest	(175)	(184)	(571)	(672)
Net Income Attributable to Kadant	$ 30,864	$ 27,487	$ 88,673	$ 94,849
Earnings per Share Attributable to Kadant (Note 3)
Basic (in dollars per share)	$ 2.64	$ 2.36	$ 7.58	$ 8.14
Diluted (in dollars per share)	$ 2.63	$ 2.35	$ 7.57	$ 8.12
Weighted Average Shares (Note 3)
Basic (in shares)	11,706	11,662	11,697	11,651
Diluted (in shares)	11,740	11,700	11,719	11,681

Earnings Per Share, Basic and Diluted EPS

No definition available.

Name:	kai_EarningsPerShareBasicAndDilutedEPSAbstract
Namespace Prefix:	kai_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.