New Accounting Pronouncements - Narrative (Details) - USD ($) $ in Thousands	Feb. 29, 2016	May. 31, 2015
New Accounting Pronouncement, Early Adoption [Line Items]
Deferred tax liabilities, noncurrent	$ 240,714	$ 339,327
New Accounting Pronouncement, Early Adoption, Effect
New Accounting Pronouncement, Early Adoption [Line Items]
Deferred tax liabilities, noncurrent		112,400
Deferred tax liabilities, current		$ 112,400