Shareholders' Equity (Schedule Of Dividends) (Details) - $ / shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Class Of Stock [Line Items]
Common stock	$ 0.050	$ 0.050
Series B [Member]
Class Of Stock [Line Items]
Cumulative Redeemable Preferred Stock	0.453	$ 0.453
Series C Preferred Stock [Member]
Class Of Stock [Line Items]
Cumulative Redeemable Preferred Stock	$ 0.406