SHAREHOLDERS' EQUITY AND EMPLOYEE BENEFIT PLANS (Narrative) (Details) shares in Millions	3 Months Ended	12 Months Ended
Sep. 30, 2017 USD ($) shares	Sep. 30, 2017 USD ($) shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description Of Maximum Percentage Of Employee Contributions and Matching Contributions Based Upon Years Of Service		employee contributions and matching Company contributions from 4% to 6%
Share-based Compensation Arrangement by Share-based Payment Award, Discount from Market Price, Offering Date		100.00%
Relative Total Shareholder Return Average Stock Price Calculation Period		90 days
Total Shareholder Return Award Performance Measurement Period		3 years
Employee Service Share-based Compensation, Cash Received from Exercise of Stock Options		$ 500,000
Grant To Non Employee Director	$ 32,500	$ 120,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent		4.00%
Share Based Compensation Arrangement By Share Based Payment Award Vesting Percentage	0.00%	0.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent		6.00%
Share Based Compensation Arrangement By Share Based Payment Award Vesting Percentage	200.00%	200.00%
Equity Incentive Plan 2009 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant \| shares	5.1	5.1

Defined benefit plan employer contribution percentage match of compensation.

No definition available.

Name:	klic_DefinedBenefitPlanEmployerContributionPercentageMatchOfCompensation
Namespace Prefix:	klic_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Grant To Non Employee Director during the reporting period.

+ References

No definition available.

+ Details

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

- Definition

The relative total shareholders' return average stock price calculation period

+ References

No definition available.

+ Details

Name:	klic_RelativeTotalShareholderReturnAverageStockPriceCalculationPeriod
Namespace Prefix:	klic_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share based compensation arrangement by share based payment award options vesting period.

+ References

No definition available.

+ Details

Name:	klic_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestingPeriod
Namespace Prefix:	klic_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The share based compensation arrangement by share based payment award vesting percentage reported.

+ References

No definition available.

+ Details

Name:	klic_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingPercentage
Namespace Prefix:	klic_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

+ Details

Name:	us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Aggregate proceeds received by the entity during the annual period from exercises of stock or unit options and conversion of similar instruments granted under equity-based payment arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationCashReceivedFromExerciseOfStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Discount rate from fair value on offering date that participants pay for shares.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPriceOfferingDate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=klic_EquityIncentivePlan2017Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: