Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Assets
Marketable securities - mutual and exchange traded funds	$ 817	$ 2,700
Investments in Hoth	10,565	10,345
Liabilities
Fair value of warrant liabilities	8	82
Quoted prices in active markets (Level 1) [Member]
Assets
Marketable securities - mutual and exchange traded funds	817	2,700
Investments in Hoth	10,084
Liabilities
Fair value of warrant liabilities
Significant other observable inputs (Level 2) [Member]
Assets
Marketable securities - mutual and exchange traded funds
Investments in Hoth
Liabilities
Fair value of warrant liabilities
Significant unobservable inputs (Level 3) [Member]
Assets
Marketable securities - mutual and exchange traded funds
Investments in Hoth		9,214
Liabilities
Fair value of warrant liabilities	$ 8	$ 82