Pension Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	May. 31, 2015
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 9,600
Interest cost	6,100
Reduction of service cost	(200)
Reduction of interest cost	(1,400)
Increase in income from continuing operations	1,600
Increase in net income	$ 1,100
Increase in basic and diluted earnings per share	$ 0.01
Pension Benefits, U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected reduction to net periodic benefit expense	$ (5,400)
Service cost	8,202	$ 7,564
Interest cost	4,499	5,002
Contribution to retirement plans in current fiscal year			$ 31,900
Contribution to retirement plans in the current remaining fiscal year	31,900
Pension Benefits, Non-U.S. Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected reduction to net periodic benefit expense	(1,000)
Service cost	1,067	1,231
Interest cost	1,323	$ 1,891
Contribution to retirement plans in current fiscal year			$ 5,700
Contribution to retirement plans in the current remaining fiscal year	$ 5,700