Basis of Presentation - Schedule of Impact of Adopting New Revenue Guidance Balance Sheet (Details) - USD ($) $ in Thousands	Aug. 31, 2018	Jun. 01, 2018	May 31, 2018	Aug. 31, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 838,192	$ 818,009	$ 804,583
Inventories, net	303,770	269,082	280,347
Income taxes, current	6,878		19,634
Prepaid expenses and other current assets	112,474	95,846	32,383
Total current assets	2,104,378	2,043,556	1,977,932
Other assets, net	221,983	216,818	29,315
Total assets	7,287,204	7,211,341	6,958,214	$ 6,851,606
Deferred income taxes	424,344	416,516	352,581
Total long-term liabilities	3,262,142	3,229,766	3,165,831
Retained earnings	6,239,535	6,027,019	5,837,827
Total shareholders’ equity	3,345,968	3,205,718	3,016,526
Total liabilities and shareholders' equity	7,287,204	$ 7,211,341	$ 6,958,214
Under Historical Guidance
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	824,328
Inventories, net	315,388
Income taxes, current	6,114
Prepaid expenses and other current assets	47,139
Total current assets	2,036,033
Other assets, net	30,321
Total assets	7,027,197
Deferred income taxes	358,188
Total long-term liabilities	3,195,986
Retained earnings	6,045,684
Total shareholders’ equity	3,152,117
Total liabilities and shareholders' equity	7,027,197
Accounting Standards Update 2014-09 | Impact of Adopting ASU 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	13,864
Inventories, net	(11,618)
Income taxes, current	764
Prepaid expenses and other current assets	65,335
Total current assets	68,345
Other assets, net	191,662
Total assets	260,007
Deferred income taxes	66,156
Total long-term liabilities	66,156
Retained earnings	193,851
Total shareholders’ equity	193,851
Total liabilities and shareholders' equity	$ 260,007