Cash and Cash Equivalents and Short-term Investments (Details)		3 Months Ended		9 Months Ended
	Aug. 02, 2016 USD ($) shares	Sep. 30, 2016 USD ($) shares	Mar. 31, 2015 USD ($) shares	Sep. 30, 2016 USD ($) shares	Sep. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Investments:
Available for sale common stock		$ 275,000		$ 275,000		$ 199,000
Total available for sale		275,000		275,000		199,000
Total short term		275,000		275,000		199,000
Total short term		$ 456,000		456,000		72,000
Proceeds from sale of assets				$ 898,000	$ 416,000
Golden Tag
Investments:
Shares received | shares	2,500,000	250,000	5,000,000	7,500,000
Additional interest in joint venture (as a percent)	10.00%	10.00%		10.00%
Estimated Fair Value.
Investments:
Available for sale common stock		$ 456,000		$ 456,000		72,000
Total available for sale.		456,000		456,000		72,000
Total short term		456,000		456,000		72,000
Carrying Value.
Investments:
Available for sale common stock		456,000		456,000		72,000
Total available for sale.		456,000		456,000		72,000
Total short term		456,000		$ 456,000		$ 72,000
San Diego
Investments:
Proceeds from sale of assets	$ 379,000
Ownership in property (as a percent)	50
San Diego | Golden Tag
Investments:
Additional interest in joint venture (as a percent)			10.00%
Extension period			2 years
Additional payments in joint venture			$ 800,000
Proceeds from sale of assets		$ 379,000
Ownership in property (as a percent)	50	50