Derivative Instruments and Hedging Activities - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Aug. 31, 2016	May 31, 2016
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Total cash collateral	$ 152,000
Aggregate impact to fair value of derivative assets and liabilities as a result of recognition on a net basis	(200,000)	$ (300,000)
Losses in accumulated other comprehensive income expected to be reclassified into net earnings	(9,008,000)
Losses in accumulated other comprehensive income expected to be reclassified into net earnings, tax	$ (5,568,000)