Summary of Acquisition (Detail) - USD ($)		12 Months Ended
		Apr. 30, 2016		Apr. 30, 2015	[2]	Mar. 01, 2015	Apr. 30, 2014
Business Acquisition [Line Items]
Receivables due from clients		$ 116,509,000	[1]	$ 3,085,000
Other current assets		15,587,000	[1]	56,000
Property and equipment		29,428,000	[1]	202,000
Intangibles assets		196,400,000	[1]	6,600,000
Other non-current assets		7,345,000	[1]	18,000
Current liabilities		125,640,000	[1]	2,635,000
Deferred compensation and other retirement plans	[1]	31,400,000
Deferred tax liabilities	[1]	58,729,000
Other liabilities		8,536,000	[1]	56,000
Net assets acquired		140,964,000	[1]	7,270,000
Purchase price		476,885,000	[1]	17,496,000			$ 0
Goodwill		335,921,000	[1]	10,226,000
Integration/acquisition costs		45,409,000	[1]	959,000
Pivot Leadership
Business Acquisition [Line Items]
Purchase price						$ 17,500,000
Pivot Leadership | Other Liabilities
Business Acquisition [Line Items]
Acquisition of a business, contingent consideration fair value		3,000,000
Hay Group
Business Acquisition [Line Items]
Goodwill		$ 335,921,000	[1]	$ 10,226,000

[1] 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.

[2] 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.