Financial instruments - Gain (losses) on derivative and non-derivative financial instruments recorded in accumulated other comprehensive (loss) (Details) - Designated as Hedging Instrument - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Cross-currency swap contracts
Derivative Instruments, Gain (Loss) [Line Items]
Derivative and non-derivative instruments gain (loss) recognized in accumulated other comprehensive income (loss)	$ 16,945	$ (21,729)	$ 29,317	$ (38,863)
Foreign denominated debt
Derivative Instruments, Gain (Loss) [Line Items]
Derivative and non-derivative instruments gain (loss) recognized in accumulated other comprehensive income (loss)	$ 10,785	$ (26,109)	$ 25,649	$ (51,836)