Pension and Other Postretirement Benefits - Components of Net Periodic Other Postretirement Benefit Cost (Details) - Other postretirement benefit plans [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023
Net periodic other postretirement benefit costs
Interest cost	$ 106	$ 104	$ 318	$ 312
Amortization of prior service credit	(63)	(68)	(190)	(203)
Recognition of actuarial loss	35	48	106	144
Net periodic other postretirement benefit cost	$ 78	$ 84	$ 234	$ 253