Intangible Assets - Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	Aug. 31, 2020	Aug. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 280,342	$ 253,098
Accumulated Amortization	159,247	128,650
Net Carrying Amount	121,095	124,448
Data content
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	35,872	32,200
Accumulated Amortization	24,847	21,512
Net Carrying Amount	11,025	10,688
Client relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	100,316	95,905
Accumulated Amortization	43,026	35,506
Net Carrying Amount	57,290	60,399
Acquired software technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	108,384	105,426
Accumulated Amortization	72,396	56,965
Net Carrying Amount	35,988	48,461
Internally developed software
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	30,276	14,262
Accumulated Amortization	13,689	10,365
Net Carrying Amount	16,587	3,897
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,388	1,311
Accumulated Amortization	1,355	1,228
Net Carrying Amount	33	83
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	4,106	3,994
Accumulated Amortization	3,934	3,074
Net Carrying Amount	$ 172	$ 920