Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity (Schedule Of Preferred Stock Outstanding) (Details)

v3.20.4
Shareholders' Equity (Schedule Of Preferred Stock Outstanding) (Details) - USD ($)
$ in Thousands
12 Months Ended
Nov. 04, 2019
Dec. 31, 2020
Dec. 31, 2019
Class of Stock [Line Items]      
Shares Outstanding   37,790 37,790
Shares Amount   $ 944,750 $ 944,750
Series W Preferred Stock [Member]      
Class of Stock [Line Items]      
Issuance Date   Oct. 01, 2016  
Earliest Potential Redemption Date   Oct. 01, 2021  
Dividend Rate   5.20%  
Shares Outstanding   7,590  
Shares Amount   $ 189,750  
Series X Preferred Stock [Member]      
Class of Stock [Line Items]      
Issuance Date   Sep. 01, 2017  
Earliest Potential Redemption Date   Sep. 01, 2022  
Dividend Rate   5.25%  
Shares Outstanding   9,200  
Shares Amount   $ 230,000  
Series Y Preferred Stock [Member]      
Class of Stock [Line Items]      
Issuance Date   Dec. 01, 2017  
Earliest Potential Redemption Date   Dec. 01, 2022  
Dividend Rate   5.20%  
Shares Outstanding   8,000  
Shares Amount   $ 200,000  
Series Z Preferred Stock [Member]      
Class of Stock [Line Items]      
Issuance Date   Nov. 01, 2019  
Earliest Potential Redemption Date   Nov. 01, 2024  
Dividend Rate 4.875% 4.875%  
Shares Outstanding   13,000  
Shares Amount $ 325,000 $ 325,000