DISCONTINUED OPERATIONS - Balance Sheets Information (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019
Assets of discontinued operations:
Total assets of discontinued operations	$ 3,204	$ 3,209
PPC and Installation Services and other discontinued activities | Discontinued Operations
Assets of discontinued operations:
Prepaid and other current assets	321	321
Other long-term assets	2,883	2,888
Total assets of discontinued operations	3,204	3,209
Liabilities of discontinued operations:
Accrued liabilities, current	3,787	4,333
Other long-term liabilities	3,216	3,331
Total liabilities of discontinued operations	$ 7,003	$ 7,664