Equities Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	May 31, 2019	May 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 8,402,229	$ 8,292,092	$ 8,165,028	$ 7,866,357	$ 7,742,948	$ 7,705,640	$ 8,165,028	$ 7,705,640
Other comprehensive income (loss), net of tax	(22,313)	14,884	389	(72)	10,111	3,019	(7,040)	13,058
Ending Balance	8,411,709	8,402,229	8,292,092	7,920,836	7,866,357	7,742,948	8,411,709	7,920,836
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(135,816)	(137,818)	(140,335)	(127,708)	(130,850)	(132,444)	(140,335)	(132,444)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(164)	102	175	0	0	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	2,564	2,564	2,565	4,841	4,451	4,214
Other Comprehensive Income (Loss), before Tax	2,400	2,666	2,740	4,841	4,451	4,214
Other Comprehensive Income (Loss), Tax	(904)	(664)	(639)	(1,424)	(1,309)	(2,620)
Other comprehensive income (loss), net of tax	1,496	2,002	2,101	3,417	3,142	1,594
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			416
Ending Balance	(134,320)	(135,816)	(137,818)	(124,291)	(127,708)	(130,850)	(134,320)	(124,291)
Accumulated Net Investment Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	0	0	8,861	17,235	13,681	10,041	8,861	10,041
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0	0	0	8,906	6,562	4,044
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0	0	0	(1,527)	0
Other Comprehensive Income (Loss), before Tax	0	0	0	8,906	5,035	4,044
Other Comprehensive Income (Loss), Tax	0	0	0	(2,620)	(1,481)	(404)
Other comprehensive income (loss), net of tax	0	0	0	6,286	3,554	3,640
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(8,861)
Ending Balance	0	0	0	23,521	17,235	13,681	0	23,521
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	3,763	(6,206)	(5,882)	(5,895)	(6,958)	(6,954)	(5,882)	(6,954)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(19,680)	18,954	(317)	160	1,081	(435)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(1,385)	(5,677)	(1,475)	425	425	429
Other Comprehensive Income (Loss), before Tax	(21,065)	13,277	(1,792)	585	1,506	(6)
Other Comprehensive Income (Loss), Tax	5,248	(3,308)	485	(172)	(443)	2
Other comprehensive income (loss), net of tax	(15,817)	9,969	(1,307)	413	1,063	(4)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			983
Ending Balance	(12,054)	3,763	(6,206)	(5,482)	(5,895)	(6,958)	(12,054)	(5,482)
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(57,295)	(60,208)	(62,559)	(50,862)	(53,214)	(51,003)	(62,559)	(51,003)
Other Comprehensive Income (Loss), before Reclassifications, before Tax		3,176	(25)	(10,442)	2,774	(612)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	(7,725)	0	0	0	0	(2,042)
Other Comprehensive Income (Loss), before Tax	(7,725)	3,176	(25)	(10,442)	2,774	(2,654)
Other Comprehensive Income (Loss), Tax	(267)	(263)	(380)	254	(422)	443
Other comprehensive income (loss), net of tax	(7,992)	2,913	(405)	(10,188)	2,352	(2,211)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			2,756
Ending Balance	(65,287)	(57,295)	(60,208)	(61,050)	(50,862)	(53,214)	(65,287)	(61,050)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(189,348)	(204,232)	(199,915)	(167,230)	(177,341)	(180,360)	(199,915)	(180,360)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(27,569)	22,232	(167)	(1,376)	10,417	2,997
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	1,179	(3,113)	1,090	5,266	3,349	2,601
Other Comprehensive Income (Loss), before Tax	(26,390)	19,119	923	3,890	13,766	5,598
Other Comprehensive Income (Loss), Tax	4,077	(4,235)	(534)	(3,962)	(3,655)	(2,579)
Other comprehensive income (loss), net of tax	(22,313)	14,884	389	(72)	10,111	3,019
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax			(4,706)
Ending Balance	$ (211,661)	$ (189,348)	$ (204,232)	$ (167,302)	$ (167,230)	$ (177,341)	$ (211,661)	$ (167,302)