DOCUMENT AND ENTITY INFORMATION - shares	9 Months Ended
	Jul. 03, 2021	Aug. 02, 2021
Entity Addresses [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jul. 03, 2021
Document Transition Report	false
Entity File Number	0-121
Entity Registrant Name	KULICKE & SOFFA INDUSTRIES INC
Entity Central Index Key	0000056978
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	23-1498399
Entity Address, Address Line One	23A Serangoon North Avenue 5
Entity Address, Address Line Two	#01-01,
Entity Address, Country	SG
Entity Address, City or Town	Singapore
Entity Address, Postal Zip Code	554369
City Area Code	215
Local Phone Number	784-6000
Title of 12(b) Security	Common Stock, Without Par Value
Trading Symbol	KLIC
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		61,968,509
Amendment Flag	false
Document Fiscal Period Focus	Q3
Document Fiscal Year Focus	2021
Current Fiscal Year End Date	--10-02
Principal Executive Offices
Entity Addresses [Line Items]
Entity Address, Address Line One	1005 Virginia Dr.
Entity Address, City or Town	Fort Washington
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19034