Preferred Stock - Additional Information (Details) - USD ($)			1 Months Ended	12 Months Ended
	Apr. 23, 2018	Feb. 18, 2015	Sep. 30, 2010	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Common stock shares outstanding				14,488,152	14,268,184
Series B redeemable preferred stock	$ 19,400,000					$ 18,900,000
Financial instruments subject to mandatory redemption, settlement terms, share value, amount	$ 2,600,000
Financial instrument obligation					$ 7,848,000
Unrealized gain (loss) on investments				$ 1,600,000	(5,300,000)
Dividend declared				$ 0	0	0
Common stock
Class of Stock [Line Items]
Common stock shares outstanding	1,307,143
Warrant
Class of Stock [Line Items]
Common stock shares outstanding	550,000
Pending Litigation | Bonanno vs. VTBH
Class of Stock [Line Items]
Loss contingency, damages sought, value		$ 15,100,000
Payments for legal settlements	$ 1,000,000
Contingent legal settlements	1,250,000
Amount of consideration allocated for litigation settlement	$ 0
Series B Redeemable Preferred Stock
Class of Stock [Line Items]
Shares issued			1,000,000
Stock issued			$ 12,400,000
Redemption price per share (in dollars per share)			$ 12.425371
Annual dividend rate (as a percentage)				8.00%
Interest expense, other				$ 0	$ 500,000	$ 1,400,000