Fair Value Measurements And Derivative Instruments (Narrative) (Details) - USD ($)			3 Months Ended		9 Months Ended
	Feb. 28, 2017	Mar. 16, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 01, 2017
Fair Value Measurements And Derivative Instruments [Line Items]
Transfers between levels			$ 0	$ 0	$ 0	$ 0
Interest Rate Derivatives [Member]
Fair Value Measurements And Derivative Instruments [Line Items]
Net gain (loss) on interest rate instruments			$ 2,000	$ 71,000	$ 139,000	$ 6,529,000
Series C Preferred Stock [Member]
Fair Value Measurements And Derivative Instruments [Line Items]
Preferred stock, annual dividend rate		6.25%
Warrants [Member]
Fair Value Measurements And Derivative Instruments [Line Items]
Adjustment to additional paid in capital, warrant		$ 611,000
Series E Preferred Stock [Member]
Fair Value Measurements And Derivative Instruments [Line Items]
Preferred stock, annual dividend rate	6.25%				6.25%
Redemption Rights [Member] | Series E Preferred Stock [Member]
Fair Value Measurements And Derivative Instruments [Line Items]
Number of shares called by redemption							490,250
Level 3 [Member] | Redemption Rights [Member] | Series E Preferred Stock [Member]
Fair Value Measurements And Derivative Instruments [Line Items]
Assets fair value	$ 150,000						$ 150,000