Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Feb. 28, 2017	May 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Settlements of contingent consideration obligations	$ 4,200
Accrued contingent payments related to new acquisitions	6,900
Fair Value, Measurements, Recurring | Foreign currency forward contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts, fair value of liability	$ 168	$ 159