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, 2020	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Net periodic pension income
Service cost	$ 452	$ 406	$ 1,346	$ 1,224
Interest cost	6,848	7,979	20,504	23,939
Expected return on plan assets	(13,539)	(13,456)	(40,491)	(40,352)
Amortization of transition obligation	23	23	67	68
Amortization of prior service cost (credit)	13	(5)	38	(15)
Recognition of actuarial losses	2,597	1,682	7,777	5,056
Settlement gain	0	0	(122)	0
Net periodic pension income	$ (3,606)	$ (3,371)	$ (10,881)	$ (10,080)