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
	Sep. 30, 2021	Sep. 30, 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)	$ 12,371	$ (17,134)
Foreign denominated debt
Derivative Instruments, Gain (Loss) [Line Items]
Derivative and non-derivative instruments gain (loss) recognized in accumulated other comprehensive income (loss)	$ 14,864	$ (25,727)