Summary of Restructuring Liability by Segment (Detail) - USD ($) $ in Thousands	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 5,962	$ 1,146	$ 2,813
Operating Segments | Executive Search
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1,594	473
Operating Segments | Executive Search | North America
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	5	51
Operating Segments | Executive Search | EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1,556	422
Operating Segments | Executive Search | Asia Pacific
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	33
Operating Segments | Hay Group
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	4,123	378
Operating Segments | Futurestep
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	245	291
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		4
Severance
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	5,293	375
Severance | Operating Segments | Executive Search
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1,566	261
Severance | Operating Segments | Executive Search | North America
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		51
Severance | Operating Segments | Executive Search | EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1,533	210
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	3,727	58
Severance | Operating Segments | Futurestep
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		52
Severance | Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		4
Facilities
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	669	771	$ 2,813
Facilities | Operating Segments | Executive Search
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	28	212
Facilities | Operating Segments | Executive Search | North America
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	5
Facilities | Operating Segments | Executive Search | EMEA
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	23	212
Facilities | Operating Segments | Hay Group
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	396	320
Facilities | Operating Segments | Futurestep
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 245	$ 239