Goodwill and Other Intangible Assets - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Nov. 30, 2019	Aug. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 324,374	$ 305,207
Accumulated Amortization	236,862	232,487
Net Carrying Amount	87,512	72,720
Customer contracts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	232,302	221,306
Accumulated Amortization	167,712	164,718
Net Carrying Amount	64,590	56,588
Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	56,397	48,838
Accumulated Amortization	35,878	34,813
Net Carrying Amount	20,519	14,025
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	35,675	35,063
Accumulated Amortization	33,272	32,956
Net Carrying Amount	$ 2,403	$ 2,107