Balance Sheet Account Details (Narrative) (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Restricted Cash and Cash Equivalents Items [Line Items]
Inventory reserves	$ 36,000	$ 80,000
4550 Towne Centre Court, San Diego, California \| Financial Standby Letter of Credit \| Letter of Credit
Restricted Cash and Cash Equivalents Items [Line Items]
Cash collateral as security	$ 900,000

Amount of valuation reserve for inventory.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant