Financial Highlights (Results Of Operations For A Share Outstanding) (Details) - $ / shares		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
Increase (Decrease) Equity Per Share [Roll Forward]
Beginning Shareholders' Equity Per Share (6/30/2015, 6/30/2014, 12/31/2014, and 12/31/2013, respectively)		$ 23.04	$ 24.53	$ 23.38	$ 24.40
Net Investment Income		0.52	0.46	1.58	1.52
Net Realized/Unrealized Gains (Losses)		(0.40)	0.02	(0.49)	0.67
Results of Operations Attributable to Equity		0.12	0.48	1.09	2.19
Less: Results of Operations Attributable to Non-controlling Interests		0.00	(0.01)	0.00	(0.03)
Results of Operations Attributable to Shareholders' Equity	[1]	0.12	0.47	1.09	2.16
Dividends Paid Per Common Share		(0.65)	(0.77)	(1.95)	(2.31)
Weighted Average Share Impact on Dividends Paid (2)	[2]	(0.01)	0.03	(0.03)	0.00
Accretive (Dilutive) Effect of Share Issuances (Net of Offering Costs), Share Repurchases, and Adjustments to Non-controlling interests		0.01	(0.18)	0.02	(0.17)
Ending Shareholders' Equity Per Share (9/30/2015, 9/30/2014, 9/30/2015, and 9/30/2014, respectively)(3)	[3]	$ 22.51	$ 24.08	$ 22.51	$ 24.08
Shares Outstanding, end of period		33,417,118	33,443,572	33,417,118	33,443,572	33,449,678	33,449,678	25,441,750	25,428,186
Shareholders Equity Per Share Upon Conversion Of All Convertible Units (in usd per share)		$ 22.22	$ 23.79	$ 22.22	$ 23.79

[1] Calculated based on average common shares outstanding and can differ from the calculation for EPS (See Note 11).

[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 September 30, 2015 and 2014, shareholders' equity per share would be $22.22 and $23.79, respectively.