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, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Earnings Per Share Disclosure [Line Items]
Net income attributable to Korn/Ferry International	$ 5,855	$ (15,995)	$ 17,971	$ 23,082	$ 25,482	$ 22,939	$ 25,403	$ 14,533	$ 30,913	$ 88,357	$ 72,691
Less: distributed and undistributed earnings to nonvested restricted stockholders									280	860
Basic net earnings attributable to common stockholders									30,633	87,497	72,691
Add: undistributed earnings to nonvested restricted stockholders									82	815
Less: reallocation of undistributed earnings to nonvested restricted stockholders									81	804
Diluted net earnings attributable to common stockholders									$ 30,634	$ 87,508	$ 72,691
Basic weighted-average number of common shares outstanding									52,372	49,052	48,162
Diluted weighted-average number of common shares outstanding									52,929	49,766	49,145
Basic earnings per share	$ 0.10	$ (0.30)	$ 0.36	$ 0.46	$ 0.51	$ 0.46	$ 0.52	$ 0.30	$ 0.58	$ 1.78	$ 1.51
Diluted earnings per share	$ 0.10	$ (0.30)	$ 0.35	$ 0.46	$ 0.51	$ 0.46	$ 0.51	$ 0.29	$ 0.58	$ 1.76	$ 1.48
ESPP
Earnings Per Share Disclosure [Line Items]
Stock									20	4
Restricted Stock
Earnings Per Share Disclosure [Line Items]
Stock									487	605	789
Stock Options
Earnings Per Share Disclosure [Line Items]
Stock									50	105	194