Financial Highlights (Results Of Operations For A Share Outstanding) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Increase (Decrease) Equity Per Share [Roll Forward]
Beginning Shareholders' Equity Per Share (12/31/2012, 12/31/2011, and 12/31/2010, respectively)	$ 24.86	[1]	$ 22.55	[1]	$ 24.47
Net Investment Income	$ 2.11		$ 1.35		$ 2.71
Net Realized/Unrealized Gains (Losses)	$ 1.26		$ 4.08		$ (2.08)
Results of Operations Attributable to Equity	$ 3.37		$ 5.43		$ 0.63
Less: Results of Operations Attributable to Non-controlling Interests	$ (0.04)		$ 0.00		$ 0.00
Results of Operations Attributable to Shareholders' Equity	$ 3.33	[2]	$ 5.43	[2]	$ 0.63	[2]
Dividends Paid Per Common Share	$ (3.83)		$ (2.50)		$ (2.51)
Weighted Average Share Impact on Dividends Paid (2)	$ (0.08)	[3]	$ (0.15)	[3]	$ (0.06)	[3]
Accretive (Dilutive) Effect of Share Issuances (Net of Offering Costs) and Share Repurchases	$ 0.12		$ (0.47)		$ 0.02
Ending Shareholders' Equity Per Share (12/31/2013, 12/31/2012, 12/31/2011, respectively)(3)	$ 24.40	[1]	$ 24.86	[1]	$ 22.55	[1]
Shares Outstanding, end of period	25,428,186		20,370,469		16,447,651		16,498,342
Shareholders Equity Per Share Upon Conversion Of All Convertible Units (in usd per share)	$ 23.99
Shareholders' equity per share upon conversion of LTIPs (in usd per share)			$ 24.38		$ 22.03

[1] If all LTIP units and OP Units (if applicable) previously issued were vested and exchanged for common shares as of December 31, 2013, 2012, and 2011, shareholders' equity per share would be $23.99, $24.38 and $22.03, respectively.

[2] Calculated based on average common shares outstanding and can differ from the calculation for EPS (See Note 9).

[3] Per share impact on dividends paid relating to share issuances/repurchases during the period as well as dividends paid to LTIP and OP Unit holders.