Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	250,000,000	250,000,000
Common stock, shares issued	156,424,000	155,264,000
Common stock, shares outstanding	156,424,000	155,264,000
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Accounts receivable from related parties	$ 20,169	$ 25,667
Securities owned, at fair value	20,261	17,319
Preferred Stock Redemption Value	50,003	71,980
WisdomTree ETF [Member]
Securities owned, at fair value	$ 19,636	$ 16,886
Series A Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	14,750	14,750
Preferred stock, shares issued	14,750	14,750
Preferred stock, shares outstanding	14,750	14,750