XML 67 R52.htm IDEA: XBRL DOCUMENT
v3.22.2

Financial Instruments - Financial Instruments and Balance Sheet Classification (Parenthetical) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Apr. 30, 2022 | Apr. 30, 2021 | Apr. 30, 2020
Investments Debt And Equity Securities [Abstract] |  |  |
Obligations for which assets are held in trust | $ 160.8 | $ 157.3 |
Income (loss) on marketable securities | (12.0) | 38.5 | $ (1.8)
Unvested obligations under deferred compensation plans | $ 24.0 | $ 26.5 |

X
- Definition The amount of the liability included in the deferred compensation plans that is unvested and therefore the participants have not earned the right to. + References No definition available. + Details
Name: | kfy_DeferredCompensationPlansUnvestedObligations
Namespace Prefix: | kfy_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of unrealized and realized gain (loss) on investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 321 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=123583765&loc=SL75117546-209714 + Details
Name: | us-gaap_EquitySecuritiesFvNiGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of the liabilities for deferred compensation arrangements classified as other. + References No definition available. + Details
Name: | us-gaap_OtherDeferredCompensationArrangementsLiabilityCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant