Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued postretirement benefits	$ 890	$ 1,068
Accrued workers’ compensation liabilities	1,702	1,495
Liability, Defined Benefit Plan, Current	1,337	305
Earnout payable	0	1,000
Working capital dispute payable	354	354
Other (including net taxes payable)	2,193	3,087
Other current liabilities	$ 6,476	$ 7,309