Equities Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2018	Nov. 30, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 8,165,028	$ 7,705,640
Other comprehensive income (loss), net of tax	389	3,019
Ending Balance	8,292,092	7,742,948
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(140,335)	(132,444)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	175	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	2,565	4,214
Other Comprehensive Income (Loss), before Tax	2,740	4,214
Other Comprehensive Income (Loss), Tax	(639)	(2,620)
Other comprehensive income (loss), net of tax	2,101	1,594
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	416
Ending Balance	(137,818)	(130,850)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	8,861	10,041
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0	4,044
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), before Tax	0	4,044
Other Comprehensive Income (Loss), Tax	0	(404)
Other comprehensive income (loss), net of tax	0	3,640
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(8,861)
Ending Balance	0	13,681
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(5,882)	(6,954)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(317)	(435)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(1,475)	429
Other Comprehensive Income (Loss), before Tax	(1,792)	(6)
Other Comprehensive Income (Loss), Tax	485	2
Other comprehensive income (loss), net of tax	(1,307)	(4)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	983
Ending Balance	(6,206)	(6,958)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(62,559)	(51,003)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(25)	(612)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	(2,042)
Other Comprehensive Income (Loss), before Tax	(25)	(2,654)
Other Comprehensive Income (Loss), Tax	(380)	443
Other comprehensive income (loss), net of tax	(405)	(2,211)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2,756
Ending Balance	(60,208)	(53,214)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(199,915)	(180,360)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(167)	2,997
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	1,090	2,601
Other Comprehensive Income (Loss), before Tax	923	5,598
Other Comprehensive Income (Loss), Tax	(534)	(2,579)
Other comprehensive income (loss), net of tax	389	3,019
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(4,706)
Ending Balance	$ (204,232)	$ (177,341)