Summary of Acquisition (Parenthetical) (Detail) - USD ($)			3 Months Ended										12 Months Ended
		Dec. 01, 2015	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	Nov. 23, 2015	Mar. 01, 2015
Business Acquisition [Line Items]
Common stock, par value			$ 0.01					$ 0.01					$ 0.01		$ 0.01
Fee revenue			$ 399,960,000		$ 344,158,000	$ 280,600,000	$ 267,394,000	$ 271,717,000		$ 249,545,000	$ 255,702,000	$ 251,188,000	$ 1,292,112,000		$ 1,028,152,000		$ 960,301,000
Assets	[1]		1,898,600,000					1,317,801,000					1,898,600,000		1,317,801,000		1,233,666,000
Adjusted EBITDA													189,709,000		161,691,000		138,294,000
Acquisition of a business, purchase price			476,885,000	[2]				17,496,000	[3]				476,885,000	[2]	17,496,000	[3]	$ 0
Legacy Hay Group
Business Acquisition [Line Items]
Business combination, aggregate purchase price		$ 476,900,000
Payment to acquire business		$ 259,000,000
Business combination, Consideration Shares		5,922,136
Business combination, Consideration Shares value		$ 217,900,000
Common stock, par value		$ 0.01
Business combination, committed to retention pool for certain employees		$ 40,000,000
Business combination, committed to retention pool for certain employees, payable		$ 5,000,000
Fee revenue													186,800,000
Assets			740,200,000										740,200,000
Adjusted EBITDA													$ 28,500,000
Adjusted EBITDA margin													14.40%
Legacy Hay Group | Payable within 45 days after November 30, 2017
Business Acquisition [Line Items]
Business combination, committed to retention pool for certain employees		50.00%
Legacy Hay Group | Payable within 45 days after November 30, 2018
Business Acquisition [Line Items]
Business combination, committed to retention pool for certain employees		50.00%
Pivot Leadership
Business Acquisition [Line Items]
Fee revenue															3,700,000
Assets								20,000,000							20,000,000
Acquisition of a business, purchase price																			$ 17,500,000
Acquisition of a business, contingent consideration			6,500,000										$ 6,500,000						$ 2,200,000
Tax deductible goodwill			$ 7,400,000					$ 8,000,000					$ 7,400,000		$ 8,000,000
Pivot Leadership | Minimum
Business Acquisition [Line Items]
Business acquisition contingent consideration payable, through year													2017
Pivot Leadership | Maximum
Business Acquisition [Line Items]
Business acquisition contingent consideration payable, through year													2020
Foreign Locations | Legacy Hay Group
Business Acquisition [Line Items]
Payment to acquire business		$ 54,000,000
Term Facility
Business Acquisition [Line Items]
Senior unsecured loan, aggregate principal amount																		$ 150,000,000

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

[2] On December 1, 2015, the Company completed its acquisition of Legacy Hay Group, a global leader in people strategy and organizational performance, for $476.9 million, net of cash acquired. The purchase price consisted of $259.0 million in cash ($54 million from foreign locations), net of estimated cash acquired and 5,922,136 shares of the Company's common stock, par value $0.01 per share (the "Consideration Shares"), representing an aggregate value of $217.9 million based on the closing price of the Company's common stock on The New York Stock Exchange on November 30, 2015. On November 23, 2015, the Company borrowed $150 million from the Term Facility, to finance a portion of the Legacy Hay Group acquisition purchase price. As part of the acquisition, the Company has committed to a $40 million retention pool (up to $5 million payable within one year of the closing of the acquisition) for certain employees of Legacy Hay Group subject to certain circumstances. Of the remaining balance, 50% will be payable within 45 days after November 30, 2017 and the remaining 50% will be payable within 45 days after November 30, 2018. The acquisition strengthens the Company's intellectual property, enhances our geographical presence, adds complimentary capabilities to further leverage search relationships and broadens capabilities for assessment and development. It improves our ability to support the global business community not only in attracting top talent and designing compensation and reward incentives, but also with an integrated approach to the entire leadership and people continuum. Actual results of operations of Legacy Hay Group are included in the Company's consolidated financial statements from December 1, 2015, the effective date of the acquisition, and includes $186.8 million, $740.2 million and $28.5 million in fee revenue, total assets and Adjusted EBITDA, respectively, with an Adjusted EBITDA margin of 14.4%, during fiscal 2016. Legacy Hay Group is included in the Hay Group segment.

[3] 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, 2016, the fair value of the contingent consideration increased to $3.0 million and 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 allows 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. Tax deductible goodwill from the Pivot Leadership acquisition was $7.4 million and $8.0 million as of April 30, 2016 and 2015, respectively.