Condensed Consolidated Balance Sheets (Unaudited) - Parenthetical - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Class A Convertible Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, liquidation value	$ 1,000,000	$ 1,000,000
Preferred stock, shares authorized (in shares)	25,000	100,000
Preferred stock, shares issued (in shares)	25,000	100,000
Preferred stock, shares outstanding (in shares)	25,000	100,000
Class A
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	38,269,000	18,096,000
Common stock, shares outstanding (in shares)	38,269,000	18,096,000
Class B
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	125,000,000	125,000,000
Common stock, shares issued (in shares)	105,813,000	114,664,000
Common stock, shares outstanding (in shares)	105,813,000	114,664,000