Equities Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2019	Nov. 30, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 8,617,530	$ 8,165,028
Other comprehensive income (loss), net of tax	(1,638)	389
Ending Balance	8,622,916	8,292,092
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(172,478)	(140,335)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(85)	175
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	4,977	2,565
Other Comprehensive Income (Loss), before Tax	4,892	2,740
Other Comprehensive Income (Loss), Tax	181	(639)
Other comprehensive income (loss), net of tax	5,073	2,101
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		416
Ending Balance	(167,405)	(137,818)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance		8,861
Other Comprehensive Income (Loss), before Reclassifications, before Tax		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		0
Other Comprehensive Income (Loss), before Tax		0
Other Comprehensive Income (Loss), Tax		0
Other comprehensive income (loss), net of tax		0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(8,861)
Ending Balance		0
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	15,297	(5,882)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(3,331)	(317)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(4,473)	(1,475)
Other Comprehensive Income (Loss), before Tax	(7,804)	(1,792)
Other Comprehensive Income (Loss), Tax	1,932	485
Other comprehensive income (loss), net of tax	(5,872)	(1,307)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		983
Ending Balance	9,425	(6,206)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(69,752)	(62,559)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(2,411)	(25)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), before Tax	(2,411)	(25)
Other Comprehensive Income (Loss), Tax	1,572	(380)
Other comprehensive income (loss), net of tax	(839)	(405)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		2,756
Ending Balance	(70,591)	(60,208)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(226,933)	(199,915)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(5,827)	(167)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	504	1,090
Other Comprehensive Income (Loss), before Tax	(5,323)	923
Other Comprehensive Income (Loss), Tax	3,685	(534)
Other comprehensive income (loss), net of tax	(1,638)	389
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(4,706)
Ending Balance	$ (228,571)	$ (204,232)