BALANCE SHEET DETAILS - Accounts and Other Receivables (Detail) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Receivables [Abstract]
Trade accounts receivable	$ 1,237,000	$ 2,972,000
Other receivables	552,000	413,000
Accounts and other receivables	$ 1,789,000	3,385,000
Estimated allowance for doubtful accounts		$ 0

Amount, after allowance for credit loss, of right to consideration from customer for product sold and service rendered in normal course of business, classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant