Consolidated Statements of Equity - USD ($) $ in Thousands	Total	Class A common stock	Class B common stock	Preferred Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Other Comprehensive Income	Accumulated Deficit	Noncontrolling Interests
Beginning Balance at Dec. 31, 2017	$ 67,128	$ 16	$ 236	$ 19,743	$ 130,870	$ (2,428)	$ 3,045	$ (67,469)	$ (16,885)
Beginning Balance, Shares at Dec. 31, 2017		1,574	23,601	2,322
Dividends on preferred stock	(1,481)							(1,481)
Dividends on common stock ($0.30 per share)	(7,774)							(7,774)
Restricted Class B common stock purchased from employees	(889)					(889)
Stock-based compensation	3,725		$ 4		3,721
Stock-based compensation, Shares			439
Sale of Class B common stock and warrants	6,000		$ 12		4,295	1,693
Sale of Class B common stock and warrants, Shares			1,152
Purchases of equity of subsidiary					(4,140)				4,140
Purchases of equity of subsidiary, Shares			42
Class B common stock issued for GRE deferred stock units	1,886		$ 3		1,883
Class B common stock issued for GRE deferred stock units, Shares			310
Noncontrolling interest from acquisition of Prism	2,667								2,667
Other comprehensive income							(454)		454
Net loss for the year ended	21,400							22,785	(1,385)
Ending Balance at Dec. 31, 2018	92,662	$ 16	$ 255	$ 19,743	136,629	(1,624)	2,591	(53,939)	(11,009)
Ending Balance, Shares at Dec. 31, 2018		1,574	25,544	2,322
Dividends on preferred stock	(1,481)							(1,481)
Adoption of ASU 2018-07					312			(312)
Dividends on common stock ($0.30 per share)	(8,114)							(8,114)
Purchase of Luma	410								410
Restricted Class B common stock purchased from employees	(467)					(467)
Stock-based compensation	1,103		$ 1		1,102
Stock-based compensation, Shares			36
Exercise of stock options	$ 1,407		$ 2		1,405
Exercise of stock options, Shares	205		205
Sale of Class B common stock and warrants	$ 325				325
Sale of Class B common stock and warrants, Shares
Purchases of equity of subsidiary	(191)				(158)				(33)
Class B common stock issued for GRE deferred stock units	(5,584)					(5,584)
Class B common stock issued for GRE deferred stock units, Shares
Other comprehensive income	(519)						(72)		(447)
Net loss for the year ended	1,379							4,175	(2,796)
Ending Balance at Dec. 31, 2019	$ 80,930	$ 16	$ 258	$ 19,743	$ 139,615	$ (7,675)	$ 2,519	$ (59,671)	$ (13,875)
Ending Balance, Shares at Dec. 31, 2019		1,574	25,785	2,322