QUARTERLY RESULTS - (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Quarterly Financial Information Disclosure [Abstract]
Interest Income	$ 37,002,000	$ 39,054,000	$ 38,590,000	$ 39,935,000	$ 40,098,000	$ 38,974,000	$ 34,579,000	$ 32,311,000
Interest expense	19,739,000	18,893,000	16,579,000	15,149,000	13,555,000	12,638,000	8,763,000	6,715,000	$ 70,360,000	$ 41,671,000	$ 15,604,000
Net interest income	17,263,000	20,161,000	22,011,000	24,786,000	26,543,000	26,336,000	25,816,000	25,596,000
Realized And Unrealized Gains	(40,707,000)	(20,150,000)	(17,734,000)	(38,055,000)	(29,540,000)	(8,254,000)	(32,597,000)	(20,727,000)
Net portfolio income	(23,444,000)	11,000	4,277,000	(13,269,000)	(2,997,000)	18,082,000	(6,781,000)	4,869,000
Management Fees	1,836,000	1,873,000	1,967,000	2,094,000	2,033,000	1,940,000	1,788,000	1,670,000
Other Expenses	1,117,000	1,097,000	964,000	1,014,000	952,000	959,000	1,074,000	750,000
Total expenses	2,953,000	2,970,000	2,931,000	3,108,000	2,985,000	2,899,000	2,862,000	2,420,000
Net income (loss)	$ (26,397,000)	$ (2,959,000)	$ 1,346,000	$ (16,377,000)	$ (5,982,000)	$ 15,183,000	$ (9,643,000)	$ 2,449,000
Earnings Per Share, Basic	$ (0.52)	$ (0.06)	$ 0.03	$ (0.31)	$ (0.12)	$ 0.33	$ (0.26)	$ 0.07	$ (0.85)	$ 0.05	$ 0.08
Earnings Per Share Diluted	$ (0.52)	$ (0.06)	$ 0.03	$ (0.31)	$ (0.12)	$ 0.33	$ (0.26)	$ 0.07	$ (0.85)	$ 0.05	$ 0.08
Weighted Average Number Of Basic Shares Outstanding	51,188,000	52,035,000	52,587,000	53,066,000	48,310,000	45,355,000	37,211,000	33,069,000	52,198,175	41,062,039	24,099,714
Dividends Declared Per Common Share	$ 0.24	$ 0.25	$ 0.27	$ 0.31	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 1.07	$ 1.68	$ 1.68