Fair Value Measurements - Fair Value of Assets and Liabilities Measured on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2015	May. 31, 2015	May. 31, 2014
Net Investment Hedge [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net liabilities	$ (4,567)	$ (4,466)	$ (1,229)
Contingent Consideration Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net liabilities	3,638	1,407	2,015
Significant Other Observable Inputs (Level 2) [Member] | Net Investment Hedge [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net liabilities	(4,567)	(4,466)	(1,229)
Significant Unobservable Inputs (Level 3) [Member] | Contingent Consideration Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net liabilities	$ 3,638	$ 1,407	$ 2,015