CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Total	BAV	Series D Convertible Preferred Stock	Common Stock	Common Stock BAV	Additional Paid-in Capital	Additional Paid-in Capital BAV	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Noncontrolling Interests in Consolidated Entities	Convertible Preferred Stock	Redeemable Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2018				2,392								8,120
Beginning balance at Dec. 31, 2018	$ 65,901			$ 24		$ 280,159		$ (214,242)	$ (498)		$ 458	$ 200,847
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation (in shares)				5
Equity-based compensation	4,812					4,836		0			(24)
Acquisition of BAV Services (in shares)					60
Acquisition of BAV Services		$ 3,748			$ 1		$ 3,747
Investment in Real Estate Advisory Holdings LLC (in shares)				17
Investment in Real Estate Advisory Holdings LLC	887					887
Amortization of preferred stock discount	(975)							(975)				$ 975
Dividends declared and undeclared - preferred stock	(5,583)
Dividends declared - preferred stock	$ (5,583)							(5,583)
Deferred compensation plan distribution (in shares)	2			2
Deferred compensation plan distribution	$ 73					73
Employee advances	353					353
Contributions from noncontrolling interests	455										455
Reallocation of carrying value	(356)					(234)					(122)		$ 356
Redemption value adjustment	13							13					(13)
Distributions to consolidated noncontrolling interests	(63)										(63)
Foreign currency translation adjustment	205								205				30
Reclassification for realized loss (gain) on available for sale securities	0
Net income (loss)	822							822					(289)
Net income (loss)	528										(294)
Ending balance (in shares) at Jun. 30, 2019				2,476								8,120
Ending balance at Jun. 30, 2019	69,998			$ 25		289,821		(219,965)	(293)		410	$ 201,822
Redeemable noncontrolling interests, beginning balance at Dec. 31, 2018													3,531
Increase (Decrease) in Temporary Equity [Roll Forward]
Reallocation of carrying value	(356)					(234)					(122)		356
Redemption value adjustment, year-to-date	13							13					(13)
Foreign currency translation adjustment	205								205				30
Net income (loss) attributable to the Company	822							822					(289)
Redeemable noncontrolling interests, ending balance at Jun. 30, 2019													3,615
Beginning balance (in shares) at Dec. 31, 2018				2,392								8,120
Beginning balance at Dec. 31, 2018	65,901			$ 24		280,159		(214,242)	(498)		458	$ 200,847
Ending balance (in shares) at Dec. 31, 2019				2,203						(2)		19,120
Ending balance at Dec. 31, 2019	42,024			$ 2		285,825		(244,084)	(216)		628
Redeemable noncontrolling interests, beginning balance at Dec. 31, 2018													3,531
Redeemable noncontrolling interests, ending balance at Dec. 31, 2019	4,131
Beginning balance (in shares) at Mar. 31, 2019				2,470								8,120
Beginning balance at Mar. 31, 2019	70,595			$ 25		287,129		(216,703)	(483)		627	$ 201,338
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation (in shares)				5
Equity-based compensation	2,654					2,681					(27)
Acquisition of BAV Services		$ (7)					$ (7)
Investment in Real Estate Advisory Holdings LLC	(113)					(113)
Amortization of preferred stock discount	(484)							(484)				$ 484
Dividends declared and undeclared - preferred stock	(2,791)
Dividends declared - preferred stock	$ (2,791)							(2,791)
Deferred compensation plan distribution (in shares)	1			1
Deferred compensation plan distribution	$ 27					27
Employee advances	104					104
Redemption value adjustment	(99)							(99)					99
Distributions to consolidated noncontrolling interests	(59)										(59)
Foreign currency translation adjustment	190								190				16
Reclassification for realized loss (gain) on available for sale securities	0
Net income (loss)	112							112					(310)
Net income (loss)	(19)										(131)
Ending balance (in shares) at Jun. 30, 2019				2,476								8,120
Ending balance at Jun. 30, 2019	69,998			$ 25		289,821		(219,965)	(293)		410	$ 201,822
Redeemable noncontrolling interests, beginning balance at Mar. 31, 2019													3,810
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption value adjustment, year-to-date	(99)							(99)					99
Foreign currency translation adjustment	190								190				16
Net income (loss) attributable to the Company	112							112					(310)
Redeemable noncontrolling interests, ending balance at Jun. 30, 2019													3,615
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	2
Additional paid-in capital	285,825
Accumulated deficit	(244,084)
Accumulated other comprehensive income (loss)	(216)
Treasury stock	(131)									$ (131)
Noncontrolling interests in consolidated entities	628
Convertible preferred stock			$ 474,060
Beginning balance (in shares) at Dec. 31, 2019				2,203						(2)		19,120
Beginning balance at Dec. 31, 2019	42,024			$ 2		285,825		(244,084)	(216)		628
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation (in shares)				330
Equity-based compensation	2,594			$ 1		2,590					3
Forfeiture of restricted common shares (in shares)				(27)						(27)
Forfeiture of restricted common shares	0					280				$ (280)
Purchase of treasury stock (in shares)				(2)						(2)
Purchase of treasury stock	(17)									$ (17)
Amortization of preferred stock discount	(1,605)							(1,605)				$ 1,605
Dividends declared and undeclared - preferred stock	(15,815)							(15,815)
Dividends declared - preferred stock	(7,940)
Deferred compensation plan distribution (in shares)				1
Deferred compensation plan distribution	6					6
Employee advances	110					110
Contributions from noncontrolling interests	77										77
Reallocation of carrying value	(56)					(37)					(19)		56
Redemption value adjustment	(509)							(509)					509
Foreign currency translation adjustment	516								516				70
Unrealized gain (loss) on available for sale securities	(800)								(800)
Reclassification for realized loss (gain) on available for sale securities	386								386
Net income (loss)	(185,636)							(185,636)					(1,084)
Net income (loss)	(186,074)										(438)
Ending balance (in shares) at Jun. 30, 2020				2,505						(31)		19,120
Ending balance at Jun. 30, 2020	(159,163)			$ 3		288,774		(447,649)	(114)	$ (428)	251	$ 475,665
Redeemable noncontrolling interests, beginning balance at Dec. 31, 2019	4,131
Increase (Decrease) in Temporary Equity [Roll Forward]
Reallocation of carrying value	(56)					(37)					(19)		56
Redemption value adjustment, year-to-date	(509)							(509)					509
Foreign currency translation adjustment	516								516				70
Net income (loss) attributable to the Company	(185,636)							(185,636)					(1,084)
Redeemable noncontrolling interests, ending balance at Jun. 30, 2020	3,682												3,682
Beginning balance (in shares) at Mar. 31, 2020				2,460						(4)		19,120
Beginning balance at Mar. 31, 2020	(142,544)			$ 2		288,114		(430,731)	(309)	$ (149)	529	$ 474,870
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Equity-based compensation (in shares)				73
Equity-based compensation	404			$ 1		403
Forfeiture of restricted common shares (in shares)				(27)						(26)
Forfeiture of restricted common shares	0					267				$ (267)
Purchase of treasury stock (in shares)				(2)						(1)
Purchase of treasury stock	(12)									$ (12)
Amortization of preferred stock discount	(795)							(795)				$ 795
Dividends declared and undeclared - preferred stock	(7,940)							(7,940)
Dividends declared - preferred stock	$ (4,002)
Deferred compensation plan distribution (in shares)	0			1
Deferred compensation plan distribution	$ 4					4
Employee advances	(14)					(14)
Redemption value adjustment	(187)							(187)					187
Foreign currency translation adjustment	128								128				19
Unrealized gain (loss) on available for sale securities	56								56
Reclassification for realized loss (gain) on available for sale securities	11								11
Net income (loss)	(7,996)							(7,996)					(644)
Net income (loss)	(8,274)										(278)
Ending balance (in shares) at Jun. 30, 2020				2,505						(31)		19,120
Ending balance at Jun. 30, 2020	(159,163)			$ 3		$ 288,774		(447,649)	(114)	$ (428)	$ 251	$ 475,665
Redeemable noncontrolling interests, beginning balance at Mar. 31, 2020													4,120
Increase (Decrease) in Temporary Equity [Roll Forward]
Redemption value adjustment, year-to-date	(187)							(187)					187
Foreign currency translation adjustment	128								$ 128				19
Net income (loss) attributable to the Company	(7,996)							$ (7,996)					(644)
Redeemable noncontrolling interests, ending balance at Jun. 30, 2020	3,682												$ 3,682
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock	3
Additional paid-in capital	288,774
Accumulated deficit	(447,649)
Accumulated other comprehensive income (loss)	(114)
Treasury stock	(428)
Noncontrolling interests in consolidated entities	$ 251
Convertible preferred stock			$ 475,665