Retirement Benefits - Net periodic pension cost recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
One-time charges related to divestitures	$ (2,480)	$ 0	$ 0
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	57,418	76,638	84,188
Interest cost	225,468	110,250	102,475
Expected return on plan assets	(311,145)	(267,888)	(267,579)
Amortization of prior service cost	931	4,103	5,325
Amortization of unrecognized actuarial loss	17,178	157,288	207,897
Amortization of transition obligation	0	8	18
Net periodic benefit cost	$ (12,630)	$ 80,399	$ 132,324