Shareholders' Equity (Schedule Of Dividends) (Parenthetical) (Details) |
3 Months Ended |
---|---|
Mar. 31, 2018 | |
Series B [Member] | |
Class Of Stock [Line Items] | |
Dividend rate percentage | 7.25% |
Series C Preferred Stock [Member] | |
Class Of Stock [Line Items] | |
Dividend rate percentage | 6.50% |