Balance Sheet Details (Accounts Payable and Accrued Liabilities) (Details) - USD ($)	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Details
Accounts payable	$ 956,000	$ 547,000
Accrued clinical trial expenses	248,000
Other accrued expenses	725,000	731,000
Accounts Payable and Accrued Liabilities, Current, Total	$ 1,929,000	$ 1,278,000