Pension Plans - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2015	Nov. 30, 2014	May. 31, 2015
Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 9,600		$ 19,200
Interest cost	6,100		12,200
Reduction of service cost	(200)		(400)
Reduction of interest cost	(1,400)		(2,800)
Increase in income from continuing operations	1,600		3,200
Increase in net income	$ 1,100		$ 2,200
Increase in basic and diluted earnings per share	$ 0.01		$ 0.02
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	16,404	$ 15,128
Interest cost	4,499	5,002	8,998	10,004
Contribution to retirement plans in current fiscal year			35,800		$ 32,000
Contribution to retirement plans in the current remaining fiscal year			3,800
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	2,134	2,462
Interest cost	$ 1,323	$ 1,891	$ 2,646	$ 3,782
Contribution to retirement plans in current fiscal year					$ 5,700