v2.4.0.6
Financial Highlights (Results Of Operations For A Share Outstanding) (Details) (USD $)
 3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Jun. 30, 2012
Dec. 31, 2011
Jun. 30, 2011
Dec. 31, 2010
Financial Highlights [Abstract]                
Beginning Shareholders' Equity Per Share $ 24.03 $ 23.31 $ 22.55 $ 24.47        
Net Investment Income $ 0.04 $ 0.67 $ 1.21 $ 2.04        
Net Realized/Unrealized Gains (Losses) $ 1.59 $ (0.74) $ 3.04 $ (1.52)        
Results of Operations $ 1.63 [1] $ (0.07) [1] $ 4.25 [1] $ 0.52 [1]        
Dividends Paid $ (0.70) $ (0.40) $ (1.80) $ (2.11)        
Weighted Average Share Impact on Dividends Paid $ (0.08) [2] $ (0.01) [2] $ (0.12) [2] $ (0.05) [2]        
Accretive (Dilutive) Effect of Share Issuances (Net of Offering Costs) and Share Repurchases $ (0.54) $ 0.01 $ (0.54) $ 0.01        
Ending Shareholders' Equity Per Share $ 24.34 [3] $ 22.84 [3] $ 24.34 [3] $ 22.84 [3]        
Shares Outstanding, end of period 20,483,696 16,489,881 20,483,696 16,489,881 16,447,651 16,447,651 16,507,381 16,498,342
Shareholders' equity per share upon conversion $ 23.88 $ 22.32 $ 23.88 $ 22.32   $ 22.03    
[1] Calculated based on average common shares outstanding and can differ from the calculation for EPS (See Note 8).
[2] Per share impact on dividends paid relating to share issuances/repurchases during the period as well as dividends paid to LTIP unit holders.
[3] If all LTIP units previously issued were vested and exchanged for common shares as of September 30, 2012 and 2011, shareholders' equity per share would be $23.88 and $22.32, respectively.