Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Class A Voting Common Stock	Common Stock Class A Voting Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance at Dec. 31, 2015	$ 182,966		$ 142,638	$ 10,270	$ 30,818	$ (760)
Beginning balance (in shares) at Dec. 31, 2015			7,521,788
Sale of common stock, net of offering costs	71,817		$ 14	71,803
Sale of common stock, net of offering costs (in shares)			13,800,000
Shares issued for asset acquisition	5,499			5,499
Shares issued for asset acquisition (in shares)			500,227
Stock-based compensation	448			448
Foreign currency translation				(760)		$ 760
Net income (loss)	(94,335)				(94,335)
Ending balance at Dec. 31, 2016	166,395		$ 142,652	87,260	(63,517)
Ending balance (in shares) at Dec. 31, 2016		21,822,015	21,822,015
Stock-based compensation	122			122
Net income (loss)	3,066				3,066
Ending balance at Mar. 31, 2017	$ 169,583		$ 142,652	$ 87,382	$ (60,451)
Ending balance (in shares) at Mar. 31, 2017		21,822,015	21,822,015