Pension and Other Postretirement Benefits - Components of Net Periodic Pension Income (Details) - Pension plans contribution [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Net periodic pension income
Service cost	$ 445	$ 407	$ 895	$ 818
Interest cost	6,832	7,970	13,656	15,960
Expected return on plan assets	(13,496)	(13,434)	(26,952)	(26,896)
Amortization of transition obligation	22	23	44	45
Amortization of prior service cost (credit)	13	(5)	25	(10)
Recognition of actuarial losses	2,585	1,679	5,180	3,374
Settlement gain	0	0	(122)	0
Net periodic pension income	$ (3,599)	$ (3,360)	$ (7,274)	$ (6,709)