Equities Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 7,905,825
Other comprehensive income (loss), net of tax	$ 10,219	$ 14,778	15,445	$ 284
Ending Balance	8,061,960		8,061,960
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			11,267	11,786
Other Comprehensive Income (Loss), before Tax			11,267	11,286
Other Comprehensive Income (Loss), Tax			(3,929)	(4,323)
Other comprehensive income (loss), net of tax			7,338	6,963
Ending Balance	(127,708)	(158,183)	(127,708)	(158,183)
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			10,606	2,827
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			(1,527)	0
Other Comprehensive Income (Loss), before Tax			9,079	2,827
Other Comprehensive Income (Loss), Tax			(1,885)	(1,083)
Other comprehensive income (loss), net of tax			7,194	1,744
Ending Balance	17,235	7,400	17,235	7,400
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			646	1,747
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			854	876
Other Comprehensive Income (Loss), before Tax			1,500	2,623
Other Comprehensive Income (Loss), Tax			(441)	(1,005)
Other comprehensive income (loss), net of tax			1,059	1,618
Ending Balance	(5,895)	(7,578)	(5,895)	(7,578)
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			1,875	(10,051)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			(2,042)	15
Other Comprehensive Income (Loss), before Tax			(167)	(10,036)
Other Comprehensive Income (Loss), Tax			21	(5)
Other comprehensive income (loss), net of tax			(146)	(10,041)
Ending Balance	(51,857)	(53,081)	(51,857)	(53,081)
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			13,127	(5,977)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax			8,552	12,677
Other Comprehensive Income (Loss), before Tax			21,679	6,700
Other Comprehensive Income (Loss), Tax			(6,234)	(6,416)
Other comprehensive income (loss), net of tax			15,445	284
Ending Balance	$ (168,225)	$ (211,442)	$ (168,225)	$ (211,442)