v3.20.4
Stockholders' Equity And Accumulated Other Comprehensive Income (Loss) (Narrative) (Details) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Sep. 15, 2025
Sep. 15, 2024
Jun. 28, 2019
Dec. 15, 2017
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
Preferred stock dividends $ (103,000,000) $ (79,000,000) $ (64,000,000)        
Stock Repurchase Program, Authorized Amount           $ 1,370,000,000  
Cash dividend declared (in dollars per share) $ 0.62 $ 0.59 $ 0.46        
Debt Instrument, Redemption, Period One [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
Preferred Stock, Redemption Terms 90 day            
Series A and B Preferred Stock [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
Preferred stock dividends $ (64,000,000) $ (64,000,000)          
Series A Preferred Stock [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
ExcessofRedemptionAmountOverCarryingAmount             $ 113,000,000
PreferredDividendsReductiontoRetainedEarningsatRedemption             100,000,000
PreferredStockIssuanceCostsReductiontoNetIncome             $ 13,000,000
Series B Preferred Stock [Member] | Subsequent Event [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
ExcessofRedemptionAmountOverCarryingAmount         $ 67,000,000    
PreferredDividendsReductiontoRetainedEarningsatRedemption         52,000,000    
PreferredStockIssuanceCostsReductiontoNetIncome         15,000,000    
Series C Preferred Stock [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
Preferred stock dividends (28,000,000) (15,000,000)          
Series C Preferred Stock [Member] | Subsequent Event [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
ExcessofRedemptionAmountOverCarryingAmount         10,000,000    
PreferredDividendsReductiontoRetainedEarningsatRedemption         $ 10,000,000    
Series D Preferred Stock              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
Preferred stock dividends (11,000,000)            
Series D Preferred Stock | Subsequent Event [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
ExcessofRedemptionAmountOverCarryingAmount       $ 4,000,000      
PreferredDividendsReductiontoRetainedEarningsatRedemption       $ 4,000,000      
Preferred Stock [Member]              
Stockholders' Equity And Comprehensive Income (Loss) [Line Items]              
Preferred stock dividends $ (103,000,000) $ (79,000,000)