Consolidated Statement of Changes in Shareholders' Equity (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
CHANGE IN SHAREHOLDERS' EQUITY RESULTING FROM OPERATIONS
Net investment income (loss)	$ 12,073,681	$ 6,677,010	$ 22,671,935	$ 14,140,039
Net realized gain (loss) on investments and financial derivatives	(3,915,741)	7,448,570	7,687,766	17,928,195
Change in net unrealized gain (loss) on investments and financial derivatives	(9,479,520)	(10,394,450)	(20,574,111)	(20,741,646)
Net increase (decrease) in shareholders' equity resulting from operations	(1,321,580)	3,731,130	9,785,590	11,326,588
CHANGE IN SHAREHOLDERS' EQUITY RESULTING FROM SHAREHOLDER TRANSACTIONS
Shares issued in connection with incentive fee payment	61,219	48,272	203,369	275,689
Dividends paid	(6,756,952)	(3,091,417)	(28,882,514)	(18,546,036)
Share-based LTIP awards	37,926	774,037	75,435	1,500,200
Net increase (decrease) in shareholders' equity from shareholder transactions	(6,657,807)	(2,269,108)	(28,603,710)	(16,770,147)
Net increase (decrease) in shareholders' equity	(7,979,387)	1,462,022	(18,818,120)	(5,443,559)
SHAREHOLDERS' EQUITY, BEGINNING OF PERIOD	392,832,979	292,888,432	403,671,712	299,794,013
SHAREHOLDERS' EQUITY, END OF PERIOD	$ 384,853,592	$ 294,350,454	$ 384,853,592	$ 294,350,454