KLA Corporation Annual report pursuant to Section 13 and 15(d)

Description of Business and Summary of Significant Accounting Policies - Summary of Significant Accounting Policies (Details)

Description of Business and Summary of Significant Accounting Policies - Summary of Significant Accounting Policies (Details) $ in Millions	12 Months Ended
	Jun. 30, 2018 USD ($) Installment customer Revenue_source	Jun. 30, 2017 USD ($) customer	Jun. 30, 2016 USD ($) customer
Summary of Significant Accounting Policies
Number of customers with significant revenue \| customer	1	2	2
Number of customers with significant A/R \| customer	3	2
Standard warranty coverage (in hours per week)	40 hours
Standard warranty coverage period (in months)	12 months
Number of revenue sources \| Revenue_source	3
Non-qualified deferred compensation plan payout period	15 years
Selling, general and administrative
Summary of Significant Accounting Policies
Executive deferred compensation program, compensation expense (benefit)	$ 19.9	$ 20.9	$ (0.8)
Gain (loss), net on deferred compensation plan assets	19.5	20.8	0.1
Cash Long-Term Incentive Plan
Summary of Significant Accounting Policies
Executive deferred compensation program, compensation expense (benefit)	$ 52.4	$ 48.8	$ 44.6
Cash Long-Term Incentive Plan \| Minimum
Summary of Significant Accounting Policies
Cash long-term incentive plan, equal vesting installments \| Installment	3
Cash long-term incentive plan, percentage of equal vesting installments	33.33%
Cash long-term incentive plan, vesting period	3 years
Cash Long-Term Incentive Plan \| Maximum
Summary of Significant Accounting Policies
Cash long-term incentive plan, equal vesting installments \| Installment	4
Cash long-term incentive plan, percentage of equal vesting installments	25.00%
Cash long-term incentive plan, vesting period	4 years