Consolidated Statement Of Assets, Liabilities And Equity (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Statement of Financial Position [Abstract]
Investments at value, cost	$ 1,693,248	$ 1,688,257
Financial derivatives–assets, at fair value Net cost	54,200	50,533
Repurchase agreements, cost	30,537	27,943
Investments sold short at value, proceeds	(846,217)	(847,602)
Financial derivatives–liabilities, at fair value Net proceeds	(28,981)	(29,746)
Securitized debt proceeds	$ (906)	$ (980)
Common stock, par value
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	25,441,750	25,428,186
Common stock, shares outstanding	25,441,750	25,428,186