Pension and Post-retirement Benefits - Net Periodic Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 1,031	$ 1,118	$ 2,064	$ 2,231
Expected return on plan assets	(1,098)	(1,113)	(2,198)	(2,221)
Amortization of net loss	15	14	28	27
Total	(52)	19	(106)	37
Post Retirement Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	22	18	43
Interest cost	13	52	25	103
Amortization of prior service credit	(369)	(135)	(737)	(269)
Amortization of net loss	47	41	94	83
Total	$ (300)	$ (20)	$ (600)	$ (40)