Organization and Summary of Significant Accounting Policies - Deferred Compensation and Pension Plans (Details)	12 Months Ended
Apr. 30, 2024
Accounting Policies [Abstract]
Percentage that actuarial gain or loss must exceed the greater of PBO or market value plan assets	10.00%

The percentage that the actuarial gain or loss must exceed the greater of the PBO or Market Related Value of Plan Assets in order to amortize the amount through pension cost.

No definition available.

Name:	kfy_CorridorRulePercentage
Namespace Prefix:	kfy_
Data Type:	dtr-types1:percentItemType
Balance Type:	na
Period Type:	duration