Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued postretirement benefits	$ 744	$ 1,068
Accrued workers’ compensation liabilities	1,466	1,495
Cumulative preferred dividends, undeclared and unpaid (1)	1,477	305
Earnout payable(2)	0	1,000
Working capital dispute payable(3)	551	354
Other(4)	2,564	3,087
Other current liabilities	$ 6,802	$ 7,309