Subsequent Events (Schedule Of Dividends Declared And Distributions Per Unit) (Details) (USD $)	3 Months Ended	12 Months Ended	3 Months Ended			0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended	0 Months Ended		3 Months Ended	0 Months Ended	3 Months Ended
	Mar. 31, 2014 Series E Cumulative Convertible Preferred Stock/Units [Member]	Dec. 31, 2013 Series E Cumulative Convertible Preferred Stock/Units [Member]	Mar. 31, 2014 Series F Cumulative Convertible Preferred Stock/Units [Member]	Mar. 31, 2014 Series G Cumulative Convertible Preferred Stock/Units [Member]	Mar. 31, 2014 Series H Cumulative Convertible Preferred Stock/Units [Member]	Apr. 29, 2014 Subsequent Event [Member] Series E Cumulative Convertible Preferred Stock/Units [Member]	Mar. 31, 2014 Subsequent Event [Member] Series E Cumulative Convertible Preferred Stock/Units [Member]	Apr. 29, 2014 Subsequent Event [Member] Series F Cumulative Convertible Preferred Stock/Units [Member]	Mar. 31, 2014 Subsequent Event [Member] Series F Cumulative Convertible Preferred Stock/Units [Member]	Apr. 29, 2014 Subsequent Event [Member] Series G Cumulative Convertible Preferred Stock/Units [Member]	Mar. 31, 2014 Subsequent Event [Member] Series G Cumulative Convertible Preferred Stock/Units [Member]	Apr. 29, 2014 Subsequent Event [Member] Series H Cumulative Convertible Preferred Stock/Units [Member]		Mar. 31, 2014 Subsequent Event [Member] Series H Cumulative Convertible Preferred Stock/Units [Member]	Apr. 29, 2014 Subsequent Event [Member] Common Stock [Member]	Mar. 31, 2014 Subsequent Event [Member] Common Stock [Member]
Subsequent Event [Line Items]
Dividend and distribution amount						$ 0.437500		$ 0.414063		$ 0.367188		$ 0.486550	[1]		$ 0.830000
Dividend and distribution payable date							Jun. 30, 2014		Jun. 30, 2014		Jun. 30, 2014			Jun. 30, 2014		Jun. 30, 2014
Dividend and distribution payable to holders of record on							Jun. 13, 2014		Jun. 13, 2014		Jun. 13, 2014			Jun. 13, 2014		Jun. 13, 2014
Annual equivalent rate of dividend and distribution	$ 1.750	$ 1.750	$ 1.656	$ 1.469	$ 1.84375	$ 1.750		$ 1.656		$ 1.46900		$ 1.844			$ 3.320

[1] Represents a pro rata dividend from and including the original issue date to and including June 30, 2014.