Goodwill and Other Intangible Assets - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Feb. 29, 2020	Aug. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 329,617	$ 305,207
Accumulated Amortization	241,262	232,487
Net Carrying Amount	88,355	72,720
Customer contracts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	233,997	221,306
Accumulated Amortization	170,780	164,718
Net Carrying Amount	63,217	56,588
Software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	59,956	48,838
Accumulated Amortization	36,940	34,813
Net Carrying Amount	23,016	14,025
Other intangible assets
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	35,664	35,063
Accumulated Amortization	33,542	32,956
Net Carrying Amount	$ 2,122	$ 2,107