Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Class A Common Stock	Series A-1 Preferred Stock	Series B Preferred Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2016	$ 159,561	$ 142,652			$ 87,260	$ (70,351)
Beginning balance (in shares) at Dec. 31, 2016		21,822,015
Shares issued for asset acquisitions	10,795			$ 3	10,792
Shares issued for asset acquisitions (in shares)			5,400	2,684,632
Conversion of Series A-2 Preferred	75,504				75,504
Conversion of Series A-2 Preferred (in shares)			76,577
Conversion of Series B Preferred		$ 3		$ (3)
Conversion of Series B Preferred (in shares)		2,684,632		(2,684,632)
Payment-in-kind dividends (in shares)			1,991
Stock-based compensation	1,315				1,315
Net loss	(43,485)					(43,485)
Ending balance at Dec. 31, 2017	203,690	$ 142,655			174,871	(113,836)
Ending balance (in shares) at Dec. 31, 2017		24,506,647	83,968
Shares issued for asset acquisition	(601)				(601)
Shares issued for asset acquisition (in shares)		139,178
Retirement of Class B Common Stock	(10)				(10)
Payment-in-kind dividends (in shares)			7,816
Stock-based compensation	119				119
Net loss	19,348					19,348
Ending balance at Dec. 31, 2018	$ 222,547	$ 142,655			$ 174,379	$ (94,487)
Ending balance (in shares) at Dec. 31, 2018		24,645,825	91,784