Condensed Consolidated Statement of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018
Management Fee Expense, Rebates	$ 400	$ 400	$ 300	$ 300
Management fee rebate					$ 1,380
Interest Expense	16,083	15,678	13,383	11,562	56,707	[1]
Interest income	35,694	35,300	31,941	28,092	131,027	[1]
Consolidated Entities [Member]
Interest Expense	1,200	700	800	900	3,600
Interest income	$ 2,100	$ 1,300	$ 1,300	$ 1,300	$ 6,000

[1] Includes interest income and interest expense of a consolidated securitization trust of $6.0 million and $3.6 million, respectively, for the year ended December 31, 2018. See Note 6 for further details on the Company's consolidated securitization trust.