Financial Highlights (Results Of Operations For A Share Outstanding) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013		Dec. 31, 2013	Dec. 31, 2012
Increase (Decrease) Equity Per Share [Roll Forward]
Beginning Shareholders' Equity Per Share (12/31/2013 and 12/31/2012, respectively)	$ 24.40		$ 24.86
Net Investment Income	$ 0.55		$ 0.52
Net Realized/Unrealized Gains (Losses)	$ 0.35		$ 1.48
Results of Operations Attributable to Equity	$ 0.90		$ 2.00
Less: Results of Operations Attributable to Non-controlling Interests	$ (0.01)		$ (0.02)
Results of Operations Attributable to Shareholders' Equity	$ 0.89	[1]	$ 1.98	[1]
Dividends Paid Per Common Share	$ (0.77)		$ (1.52)
Weighted Average Share Impact on Dividends Paid (2)	$ (0.02)	[2]	$ (0.05)	[2]
Accretive (Dilutive) Effect of Share Issuances (Net of Offering Costs), Share Repurchases, and Adjustments to Non-controlling Interest	$ (0.01)		$ 0.01
Ending Shareholders' Equity Per Share (3/31/2014 and 3/31/2013, respectively)(3)	$ 24.49	[3]	$ 25.28	[3]
Shares Outstanding, end of period	25,441,750		20,403,723		25,428,186	20,370,469
Shareholders Equity Per Share Upon Conversion Of All Convertible Units (in usd per share)	$ 24.10		$ 24.78

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

[2] 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.

[3] If all LTIP units and OP Units previously issued were vested and exchanged for common shares as of March 31, 2014 and 2013, shareholders' equity per share would be $24.10 and $24.78, respectively.