Earnings Per Share Disclosure [Line Items]

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- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

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- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities, and addition from assumption of issuance of common shares for dilutive potential common shares; of income (loss) available to common shareholders.

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- Definition

Amount of earnings (loss) distributed and earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.

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- Definition

Amount of undistributed earnings (loss) allocated to participating securities for the basic earnings (loss) per share or per unit calculation under the two-class method.

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- Definition

Amount of undistributed earnings (loss) allocated to participating securities for the diluted earnings (loss) per share or per unit calculation under the two-class method.

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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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Basic and Diluted Earnings per Common Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2016
Earnings Per Share Disclosure [Line Items]
Net income attributable to Korn/Ferry International	$ 41,160	$ 27,247	$ 36,331	$ 29,041	$ 26,924	$ 23,897	$ 30,152	$ 3,208	$ 133,779	$ 84,181	$ 30,913
Less: distributed and undistributed earnings to nonvested restricted stockholders									1,426	765	280
Basic net earnings attributable to common stockholders									132,353	83,416	30,633
Add: undistributed earnings to nonvested restricted stockholders									1,187	560	82
Less: reallocation of undistributed earnings to nonvested restricted stockholders									1,169	553	81
Diluted net earnings attributable to common stockholders									$ 132,371	$ 83,423	$ 30,634
Basic weighted-average number of common shares outstanding									55,426	56,205	52,372
Diluted weighted-average number of common shares outstanding									56,254	56,900	52,929
Basic earnings per share	$ 0.74	$ 0.49	$ 0.65	$ 0.52	$ 0.48	$ 0.42	$ 0.53	$ 0.06	$ 2.39	$ 1.48	$ 0.58
Diluted earnings per share	$ 0.73	$ 0.48	$ 0.64	$ 0.51	$ 0.47	$ 0.42	$ 0.52	$ 0.06	$ 2.35	$ 1.47	$ 0.58
ESPP
Earnings Per Share Disclosure [Line Items]
Stock									1	25	20
Restricted Stock
Earnings Per Share Disclosure [Line Items]
Stock									822	646	487
Stock Options
Earnings Per Share Disclosure [Line Items]
Stock									5	24	50