CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accounts receivable, net of allowance	$ 5	$ 5
Investments - related parties, original issue discount	$ 2,579	$ 2,115
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, authorized	25,000,000	25,000,000
Convertible preferred stock, issued	125,000	478,776
Convertible preferred stock, outstanding	125,000	478,776
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized	23,651,224	23,651,224
Preferred stock, issued
Preferred stock, outstanding
Series B Preferred Stock [Member]
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, authorized	500,000	500,000
Convertible preferred stock, issued	125,000	100,000
Convertible preferred stock, outstanding	125,000	100,000
Convertible preferred stock, stated value (in dollars per share)	$ 10	$ 10
Convertible preferred stock, liquidation preference	$ 1,250	$ 1,000
Series C Preferred Stock [Member]
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, authorized	460,000	460,000
Convertible preferred stock, issued
Convertible preferred stock, outstanding
Convertible preferred stock, stated value (in dollars per share)	$ 2.40	$ 2.40
Series D Preferred Stock [Member]
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, authorized	378,776	378,776
Convertible preferred stock, issued		378,776
Convertible preferred stock, outstanding		378,776
Convertible preferred stock, stated value (in dollars per share)	$ 0.01	$ 0.01
Convertible preferred stock, liquidation preference		$ 4
Series E Preferred Stock [Member]
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, authorized	10,000	10,000
Convertible preferred stock, issued
Convertible preferred stock, outstanding
Convertible preferred stock, stated value (in dollars per share)	$ 45	$ 45
Common Class A [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized	200,000,000	200,000,000
Common stock, issued	69,341,486	30,222,299
Common stock, outstanding	69,341,486	30,222,299
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized	25,000,000	25,000,000
Common stock, issued
Common stock, outstanding