Earnings per share - Computation of basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Dec. 31, 2022	Dec. 31, 2021		Dec. 31, 2022	Dec. 31, 2021	[1],[2]
Numerator:
Net income attributable to common shareholders, basic	$ 395,237	$ 387,600	[1]	$ 783,091	$ 838,757
Net income attributable to common shareholders, diluted	$ 395,237	$ 387,600		$ 783,091	$ 838,757
Denominator:
Basic - weighted average common shares (in shares)	128,313,322	128,493,725		128,369,162	128,610,223
Increase in weighted average common shares from dilutive effect of equity-based awards (in shares)	1,731,691	2,087,940		1,592,534	1,974,989
Diluted - weighted average common shares, assuming exercise of equity-based awards (in shares)	130,045,013	130,581,665		129,961,696	130,585,212
Basic earnings per share (in USD per share)	$ 3.08	$ 3.02	[1],[2]	$ 6.10	$ 6.52
Diluted earnings per share (in USD per share)	$ 3.04	$ 2.97	[1],[2]	$ 6.03	$ 6.42

[1] *Prior period amounts have been reclassified to reflect the income statement reclassification as described in Note 1.

[2] *Prior period amounts have been reclassified to reflect the income statement reclassification as described in Note 1.