Income Taxes (Additional Information) (Details) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Aug. 31, 2018 USD ($)	Aug. 31, 2018 USD ($) $ / shares	Aug. 31, 2017 USD ($) $ / shares	Aug. 31, 2016 USD ($) $ / shares
Income Tax Disclosure [Abstract]
Tax Cuts and Jobs Act, provisional income tax expense	$ 111,400	$ 142,300
Tax Cuts and Jobs Act, one-time mandatory repatriation tax	24,900	65,900
Tax Cuts and Jobs Act, re-measurement of deferred taxes		(10,500)
Tax Cuts and Jobs Act, change in indefinite reinvestment assertion on certain earnings from foreign subsidiaries	85,000	$ 85,000
Net increase in effective tax rate		0.298
Income Taxes [Line Items]
Income tax benefit on income from subsidiaries		$ 52,100	$ 38,600	$ 50,500
Per basic share income tax benefit on income from subsidiaries (in dollars per share) | $ / shares		$ 0.30	$ 0.22	$ 0.27
Net change in the total valuation allowance		$ (62,100)	$ (59,300)
Undistributed foreign earnings upon which taxes had not been provided	85,000	85,000
Deferred tax liability on undistributed earnings of foreign subsidiaries	74,654	74,654	86,202
Undistributed earnings of foreign subsidiaries	2,400,000	2,400,000
Possible adjustments for transfer pricing and certain inclusions in taxable income	106,100	106,100
Accrued interest and penalties related to unrecognized tax benefits included in income tax provision	20,400	20,400	27,100
Recognized (derecognized) tax benefit, accrued interest and penalties		(6,700)	$ 5,200	$ 1,800
Fiscal Years 2009 Through 2011
Income Taxes [Line Items]
Potential additional income tax payment due	28,600	28,600
Fiscal Years 2012 Through 2014
Income Taxes [Line Items]
Potential additional income tax payment due	5,300	5,300
U.S.
Income Taxes [Line Items]
Tax credit carry forwards	65,600	65,600
State and Local Jurisdiction
Income Taxes [Line Items]
Net operating loss carry forwards	55,400	55,400
Tax credit carry forwards	4,800	4,800
Non U.S.
Income Taxes [Line Items]
Net operating loss carry forwards	318,000	318,000
Non U.S. | Investment Tax Credit
Income Taxes [Line Items]
Tax credit carry forwards	$ 23,300	$ 23,300