Consolidated Statement Of Changes In Shareholders' Equity (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Net investment income	$ 24,187		$ 44,695		$ 24,787
Net realized gain (loss) on investments and financial derivatives	(11,247)		26,831		25,161
Change in net unrealized gain (loss) on investments and financial derivatives	84,206		(61,199)		(9,377)
Net increase in shareholders’ equity resulting from operations	97,146		10,327		40,571
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM SHAREHOLDER TRANSACTIONS
Net proceeds from the issuance of shares(1)	88,142	[1]	0	[1]	98,310	[1]
Shares issued in connection with incentive fee payment	1,180		203		528
Dividends paid(2)	(47,412)	[2],[3]	(42,382)	[2],[3]	(33,906)	[2],[3]
Shares repurchased	(3,430)		(1,051)		0
Net offering costs	(322)		0		(3,612)
Share-based LTIP awards	135		147		1,987
Net increase (decrease) in shareholders’ equity from shareholder transactions	38,293		(43,083)		63,307
Net increase (decrease) in shareholders’ equity	135,439		(32,756)		103,878
SHAREHOLDERS’ EQUITY, BEGINNING OF PERIOD	370,916		403,672		299,794
SHAREHOLDERS’ EQUITY, END OF PERIOD	$ 506,355		$ 370,916		$ 403,672

[1] Proceeds from the issuance of shares are net of underwriters’ discount in the amount of $1,852 and $2,940 for the years ended December 31, 2012 and 2010, respectively.

[2] For the years ended December 31, 2012, 2011, and 2010, dividends totaling $ 2.50, $2.51, and $2.45, respectively, per common share and LTIP unit outstanding were declared and paid.

[3] The Company pays quarterly dividends in arrears, so a portion of the dividends paid in each calendar year relate to the prior year’s earnings.