Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Investments measured at fair value	$ 385,276	$ 329,435
Assets sold under agreements to repurchase at fair value	$ 96,505	$ 98,085
Class A Shares
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	22,311,432	21,284,945
Common stock, shares outstanding	22,311,432	21,284,945
Class B Shares
Common stock, par value per share	$ 0.01	$ 0.01
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	32,820,414	29,208,952
Common stock, shares outstanding	32,820,414	29,208,952