Reconciliation of 35% Federal Statutory Tax Rate to Total Tax Provision (Detail)	12 Months Ended
	May 31, 2016	May 31, 2015	May 31, 2014
Reconciliation of Statutory Federal Tax Rate [Line Items]
Federal statutory rate	35.00%	35.00%	35.00%
State and local income taxes, net of federal tax benefit	2.60%	3.00%	2.00%
Change in state and local valuation allowances	(1.10%)	(1.10%)	(0.90%)
Non-U.S. income taxes at other than 35%	(3.50%)	(0.70%)	(1.00%)
Change in Non-U.S. valuation allowances	0.50%	1.20%	1.40%
Qualified production activities deduction	(2.20%)	(5.90%)	(3.90%)
Acquisition of an additional 10% interest in TWB			(3.40%)
Research & development credits	(0.20%)	(0.20%)	(1.10%)
Tax write off of investment in foreign subsidiary			(1.10%)
Benefit related to foreign tax credits		(5.30%)
Excess benefit related to share-based payment awards	(1.60%)
Other	(0.40%)	(0.90%)	0.50%
Effective tax rate attributable to controlling interest	29.10%	25.10%	27.50%