Annual report pursuant to Section 13 and 15(d)

Summary of Restructuring Liability by Segment (Detail)

v3.7.0.1
Summary of Restructuring Liability by Segment (Detail) - USD ($)
$ in Thousands
Apr. 30, 2017
Apr. 30, 2016
Apr. 30, 2015
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve $ 13,695 $ 5,962 $ 1,146
Operating Segments | Executive Search      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 870 1,594  
Operating Segments | Executive Search | North America      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 384 5  
Operating Segments | Executive Search | EMEA      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 393 1,556  
Operating Segments | Executive Search | Asia Pacific      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 6 33  
Operating Segments | Executive Search | Latin America      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 87    
Operating Segments | Hay Group      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 12,693 4,123  
Operating Segments | Futurestep      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 132 245  
Severance      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 5,341 5,293 375
Severance | Operating Segments | Executive Search      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 527 1,566  
Severance | Operating Segments | Executive Search | North America      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 134    
Severance | Operating Segments | Executive Search | EMEA      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 393 1,533  
Severance | Operating Segments | Executive Search | Asia Pacific      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve   33  
Severance | Operating Segments | Hay Group      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 4,814 3,727  
Facilities      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 8,354 669 $ 771
Facilities | Operating Segments | Executive Search      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 343 28  
Facilities | Operating Segments | Executive Search | North America      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 250 5  
Facilities | Operating Segments | Executive Search | EMEA      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve   23  
Facilities | Operating Segments | Executive Search | Asia Pacific      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 6    
Facilities | Operating Segments | Executive Search | Latin America      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 87    
Facilities | Operating Segments | Hay Group      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve 7,879 396  
Facilities | Operating Segments | Futurestep      
Restructuring Cost and Reserve [Line Items]      
Restructuring Reserve $ 132 $ 245