Equities Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 7,905,825
Other comprehensive income (loss), net of tax	$ (1,501)	$ 1,742	13,944	$ 2,026
Ending Balance	8,162,533		8,162,533
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(135,046)	(165,146)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			0	(500)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			16,108	17,679
Other Comprehensive Income (Loss), before Tax			16,108	17,179
Other Comprehensive Income (Loss), Tax			(5,353)	(6,580)
Other comprehensive income (loss), net of tax			10,755	10,599
Ending Balance	(124,291)	(154,547)	(124,291)	(154,547)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			10,041	5,656
Other Comprehensive Income (Loss), before Reclassifications, before Tax			19,512	2,637
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			(1,527)	0
Other Comprehensive Income (Loss), before Tax			17,985	2,637
Other Comprehensive Income (Loss), Tax			(4,505)	(1,010)
Other comprehensive income (loss), net of tax			13,480	1,627
Ending Balance	23,521	7,283	23,521	7,283
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(6,954)	(9,196)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			806	1,920
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			1,279	1,311
Other Comprehensive Income (Loss), before Tax			2,085	3,231
Other Comprehensive Income (Loss), Tax			(613)	(1,238)
Other comprehensive income (loss), net of tax			1,472	1,993
Ending Balance	(5,482)	(7,203)	(5,482)	(7,203)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(51,711)	(43,040)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			(9,996)	(12,537)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			(2,042)	15
Other Comprehensive Income (Loss), before Tax			(12,038)	(12,522)
Other Comprehensive Income (Loss), Tax			275	329
Other comprehensive income (loss), net of tax			(11,763)	(12,193)
Ending Balance	(63,474)	(55,233)	(63,474)	(55,233)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(183,670)	(211,726)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			10,322	(8,480)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			13,818	19,005
Other Comprehensive Income (Loss), before Tax			24,140	10,525
Other Comprehensive Income (Loss), Tax			(10,196)	(8,499)
Other comprehensive income (loss), net of tax			13,944	2,026
Ending Balance	$ (169,726)	$ (209,700)	$ (169,726)	$ (209,700)