Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued postretirement benefits	$ 1,068	$ 1,068
Accrued workers’ compensation liabilities	1,598	1,495
Earnout payable	0	1,000
Working capital dispute payable	354	354
Other (including net taxes payable)	4,004	3,392
Other current liabilities	$ 7,024	$ 7,309