OTHER FINANCIAL DATA Other Financial Data (Details) - USD ($) $ in Thousands	12 Months Ended
Oct. 03, 2020	Sep. 28, 2019	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Incentive Compensation Expense	$ 18,524	$ 423	$ 25,607
Warranty and Retrofit Expense	$ 8,692	$ 13,030	$ 13,110

Amount of selling general and administrative incentive compensation expenses during the reporting period.

No definition available.

Name:	klic_SellingGeneralAndAdministrativeIncentiveCompensationExpense
Namespace Prefix:	klic_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration