Accumulated Other Comprehensive Income (Change in AOCI, Net of Tax) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	$ 1,759,140	$ 1,858,852	$ 1,900,758	$ 1,963,380
Other comprehensive (loss) income before reclassifications			(85,964)
Amounts reclassified from AOCI			19,355
Total other comprehensive (loss) income	(46,460)	(36,752)	(66,609)	(30,606)
Ending Balance	1,645,304	1,867,200	1,645,304	1,867,200
Foreign Currency Translation Adjustment
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance			(14,298)
Other comprehensive (loss) income before reclassifications			(43,010)
Amounts reclassified from AOCI			0
Total other comprehensive (loss) income			(43,010)
Ending Balance	(57,308)		(57,308)
Derivative Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance			(39,398)
Derivative Instruments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Other comprehensive (loss) income before reclassifications			(21,391)
Amounts reclassified from AOCI			19,355
Total other comprehensive (loss) income			(2,036)
Ending Balance	(41,434)		(41,434)
Actuarial Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance			(28,033)
Other comprehensive (loss) income before reclassifications			0
Amounts reclassified from AOCI			0
Total other comprehensive (loss) income			0
Ending Balance	(28,033)		(28,033)
Prior Service Cost
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance			(608)
Other comprehensive (loss) income before reclassifications			0
Amounts reclassified from AOCI			0
Total other comprehensive (loss) income			0
Ending Balance	(608)		(608)
Available for Sale Securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance			(457)
Other comprehensive (loss) income before reclassifications			(21,563)
Amounts reclassified from AOCI			0
Total other comprehensive (loss) income			(21,563)
Ending Balance	(22,020)		(22,020)
AOCI Attributable to Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning Balance	(102,943)	(13,253)	(82,794)	(19,399)
Total other comprehensive (loss) income	(46,460)	(36,752)	(66,609)	(30,606)
Ending Balance	$ (149,403)	$ (50,005)	$ (149,403)	$ (50,005)