Pension and Other Postretirement Benefits - Components of Net Periodic Pension Income (Details) - Pension plans contribution [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Net periodic pension income
Service cost	$ 429	$ 452	$ 1,264	$ 1,346
Interest cost	5,815	6,848	17,371	20,504
Expected return on plan assets	(13,459)	(13,539)	(40,171)	(40,491)
Amortization of transition obligation	24	23	70	67
Amortization of prior service cost (credit)	8	13	25	38
Recognition of actuarial losses	3,431	2,597	10,190	7,777
Settlement gain	0	0	0	(122)
Net periodic pension income	$ (3,752)	$ (3,606)	$ (11,251)	$ (10,881)