Balance Sheet Details (Accounts Payable and Accrued Liabilities) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Balance Sheet Details [Abstract]
Accounts payable	$ 578,000	$ 1,056,000
Accrued compensation	1,050,000	895,000
Other accrued expenses	302,000	746,000
Dividends payable	38,000	38,000
Accounts payable and accrued expenses	$ 1,968,000	$ 2,735,000