Summary of Acquisition (Parenthetical) (Detail)		3 Months Ended									12 Months Ended
		Apr. 30, 2015 USD ($) Country		Jan. 31, 2015 USD ($)	Oct. 31, 2014 USD ($)	Jul. 31, 2014 USD ($)	Apr. 30, 2014 USD ($)	Jan. 31, 2014 USD ($)	Oct. 31, 2013 USD ($)	Jul. 31, 2013 USD ($)	Apr. 30, 2015 USD ($) Country Product		Apr. 30, 2014 USD ($)	Apr. 30, 2013 USD ($)		Mar. 01, 2015 USD ($)	Dec. 31, 2012 USD ($)	Sep. 01, 2012 USD ($)
Business Acquisition [Line Items]
Acquisition of a business, purchase price		$ 17,496,000	[1]				$ 0				$ 17,496,000	[1]	$ 0	$ 126,917,000	[2],[3]
Fee revenue		271,717,000		$ 249,545,000	$ 255,702,000	$ 251,188,000	251,712,000	$ 242,184,000	$ 237,968,000	$ 228,437,000	1,028,152,000		960,301,000	812,831,000
Total assets	[4]	$ 1,317,801,000					$ 1,233,666,000				$ 1,317,801,000		1,233,666,000	$ 1,115,229,000
Payment of contingent consideration from acquisitions													15,000,000
Number of countries in which entity operates | Country		37									37
PDI Ninth House
Business Acquisition [Line Items]
Acquisition of a business, purchase price																	$ 92,500,000
Acquisition of a business, contingent consideration																	$ 14,900,000
Payment of contingent consideration from acquisitions													$ 15,000,000
Pivot Leadership
Business Acquisition [Line Items]
Acquisition of a business, purchase price																$ 17,500,000
Acquisition of a business, contingent consideration		$ 6,500,000									$ 6,500,000					$ 2,200,000
Fee revenue											3,700,000
Total assets		$ 20,000,000									$ 20,000,000
Global Novations, LLC
Business Acquisition [Line Items]
Acquisition of a business, purchase price																		$ 34,500,000
Minimum | PDI Ninth House
Business Acquisition [Line Items]
Number of years in business											45 years
Number of countries in which entity operates | Country		20									20
Minimum | Pivot Leadership
Business Acquisition [Line Items]
Business acquisition contingent consideration payable, through year											2017
Minimum | Global Novations, LLC
Business Acquisition [Line Items]
Number of years in business											30 years
Offerings designed to develop leaders | Product											150
Number of countries in which the entity has provided services | Country		40									40
Maximum | Pivot Leadership
Business Acquisition [Line Items]
Business acquisition contingent consideration payable, through year											2020

[1] On March 1, 2015, the Company acquired all outstanding membership interest of Pivot Leadership, a global provider of innovative, customized and scalable executive development programs, for $17.5 million, net of cash acquired, which includes $2.2 million in contingent consideration. As of April 30, 2015, the contingent consideration is included in other liabilities in the accompanying consolidated balance sheets. The contingent consideration is based on the achievement of certain revenue targets and can be up to $6.5 million, payable in four installments in fiscal 2017 to 2020. The acquisition will allow us to integrate the Company's talent management solution with Pivot's executive learning capabilities. Actual results of operations of Pivot Leadership are included in the Company's consolidated financial statements from March 1, 2015, the effective date of the acquisition, and include $3.7 million and $20.0 million in fee revenue and total assets, respectively, during fiscal 2015.

[2] On December 31, 2012, the Company acquired all outstanding shares of Minneapolis-based PDI, a leading, globally-recognized provider of leadership assessment and development solutions, for $92.5 million, net of cash acquired, which includes $14.9 million in contingent consideration, for the achievement of certain post-closing synergies. During fiscal 2014, the Company paid $15.0 million (includes the interest accreted since December 31, 2012) in contingent consideration to the selling stockholders of PDI as a result of the achievement of certain pre-determined goals associated with expense synergies. PDI has been in business for over 45 years and operates in more than 20 global locations. The acquisition strengthens and expands the Company's talent management offerings through adding complementary product and service offerings and rich intellectual property. Actual results of operations of PDI are included in the Company's consolidated financial statements from December 31, 2012, the effective date of the acquisition.

[3] On September 1, 2012, the Company acquired all outstanding membership interests of Global Novations, LLC, ("Global Novations") a leading provider of diversity and inclusion and leadership development solutions, for $34.5 million in cash, net of cash acquired. Global Novations has more than 150 offerings designed to develop leaders, enable high-performing cultures and deliver business outcomes for its clients. Key diversity and inclusion and leadership offerings include consulting, training and education and e-learning. Global Novations has more than 30 years of experience and has served clients in more than 40 countries, including more than half of the Fortune 100. The acquisition strengthens and expands the Company's talent management offerings through adding complementary product and service offerings and rich intellectual property. Actual results of operations of Global Novations are included in the Company's consolidated financial statements from September 1, 2012, the effective date of the acquisition.

[4] As of the end of the fiscal year.