QUARTERLY RESULTS - (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Interest Income	$ 40,098,000	$ 38,974,000	$ 34,579,000	$ 32,311,000	$ 25,068,000	$ 22,358,000	$ 19,235,000	$ 20,466,000
Interest Expense	13,555,000	12,638,000	8,763,000	6,715,000	4,976,000	3,979,000	3,330,000	3,319,000
Net interest income	26,543,000	26,336,000	25,816,000	25,596,000	20,092,000	18,379,000	15,905,000	17,147,000
Realized And Unrealized Gains	(29,540,000)	(8,254,000)	(32,597,000)	(20,727,000)	(38,003,000)	4,418,000	(7,308,000)	(19,558,000)
Net portfolio income	(2,997,000)	18,082,000	(6,781,000)	4,869,000	(17,911,000)	22,797,000	8,597,000	(2,411,000)
Management Fees	2,033,000	1,940,000	1,788,000	1,670,000	1,557,000	1,388,000	1,274,000	1,269,000
OtherExpenses	952,000	959,000	1,074,000	750,000	951,000	883,000	860,000	911,000
Total expenses	2,985,000	2,899,000	2,862,000	2,420,000	2,508,000	2,271,000	2,134,000	2,180,000
Net income (loss)	$ (5,982,000)	$ 15,183,000	$ (9,643,000)	$ 2,449,000	$ (20,419,000)	$ 20,526,000	$ 6,463,000	$ (4,591,000)
Earnings Per Share, Basic	$ (0.12)	$ 0.33	$ (0.26)	$ 0.07	$ (0.72)	$ 0.85	$ 0.29	$ (0.21)	$ 0.05	$ 0.08	$ 0.05
Earnings Per Share Diluted	$ (0.12)	$ 0.33	$ (0.26)	$ 0.07	$ (0.72)	$ 0.85	$ 0.29	$ (0.21)	$ 0.05	$ 0.08	$ 0.05
Weighted Average Number Of Basic Shares Outstanding	48,310,000	45,355,000	37,211,000	33,069,000	28,495,000	24,133,000	21,921,000	21,756,000	41,062,039	24,099,714	20,266,706
Dividends Declared Per Common Share	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 0.42	$ 1.68	$ 1.68	$ 1.92