Liability Related to the Sale of Future Proceeds from Disposition of Subsidiary (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018
Liability Related To Sale Of Future Proceeds From Disposition Of Subsidiary Details Abstract
Liabilities related to sale of future proceeds from disposition of subsidiaries – beginning balance
Cash received from sale of future proceeds from disposition of subsidiary		800,000
Non-Cash other income recognized	$ 0	(109,000)
Non-Cash interest expense recognized	0	33,000
Liabilities related to sale of future proceeds from disposition of subsidiary – ending balance	$ 724,000	724,000
Less: unamortized transaction costs		(3,000)
Liability related to sale of future proceeds from disposition of subsidiary, net		$ 721,000