Derivative Instruments - Hedging Positions and Corresponding Fair Values (Details) $ in Thousands	Aug. 31, 2020 PHP (₱)	Aug. 31, 2020 INR (₨)	Aug. 31, 2020 EUR (€)	Aug. 31, 2020 GBP (£)	Aug. 31, 2020 USD ($)	Aug. 31, 2019 USD ($)
Derivative [Line Items]
Gross notional value	₱ 1,300,000,000	₨ 1,400,000,000	€ 31,800,000	£ 36,400,000
Cash Flow Hedging | Designated as Hedging Instrument
Derivative [Line Items]
Gross notional value					$ 417,149	$ 113,700
Cash Flow Hedging | Designated as Hedging Instrument | Foreign currency forward contracts
Derivative [Line Items]
Gross notional value					129,649	113,700
Cash Flow Hedging | Designated as Hedging Instrument | Interest rate swap agreement
Derivative [Line Items]
Gross notional value					$ 287,500	$ 0