DOCUMENT AND ENTITY INFORMATION - shares	6 Months Ended
	Mar. 28, 2020	Apr. 24, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	0-121
Entity Registrant Name	KULICKE & SOFFA INDUSTRIES INC
Entity Central Index Key	0000056978
Amendment Flag	false
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, Address Line Three	K&S Corporate Headquarters
Entity Address, City or Town	Singapore
Entity Address, Country	SG
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
Current Fiscal Year End Date	--10-03
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Document Period End Date	Mar. 28, 2020
Document Fiscal Period Focus	Q2
Document Fiscal Year Focus	2020
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		62,427,723