Consolidated Statements of Changes in Stockholders' Equity - USD ($)
shares in Millions, $ in Millions
Total
Common Stock
Paid-in Capital
Accumulated Deficit
Accumulated Other Comprehensive Loss
Treasury Stock
Beginning Balance (in shares) at Dec. 31, 2016   181.8       (3.7)
Beginning Balance at Dec. 31, 2016 $ 5,218 $ 2 $ 6,388 $ (873) $ (86) $ (213)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Net income attributable to common shareholders 426     426    
Direct stock reinvestment and purchase plan (in shares)   0.1        
Direct stock reinvestment and purchase plan 8   8      
Employee stock purchase plan (in shares)   0.1        
Employee stock purchase plan 7   7      
Stock-based compensation activity (in shares)   0.5       (0.1)
Stock-based compensation activity 15   22 0   $ (7)
Acquisition via treasury stock (in shares)           0.4
Acquisitions via treasury stock 34   7     $ 27
Repurchases of common stock (in shares)           (0.7)
Repurchases of common stock (54)         $ (54)
Net other comprehensive income 7       7  
Dividends (declared per common share) (297)     (297)    
Ending Balance (in shares) at Dec. 31, 2017   182.5       (4.1)
Ending Balance at Dec. 31, 2017 5,385 $ 2 6,432 (723) (79) $ (247)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Net income attributable to common shareholders 567     567    
Direct stock reinvestment and purchase plan (in shares)   0.1        
Direct stock reinvestment and purchase plan 8   8      
Employee stock purchase plan (in shares)   0.1        
Employee stock purchase plan 8   8      
Stock-based compensation activity (in shares)   0.4       (0.1)
Stock-based compensation activity $ 20   26 (1)   $ (5)
Issuance of common stock (in shares) 2.3          
Issuance of common stock $ 183   183      
Repurchases of common stock (in shares) (0.6)         (0.5)
Repurchases of common stock $ (45)         $ (45)
Net other comprehensive income 45       45  
Dividends (declared per common share) (327)     (327)    
Ending Balance (in shares) at Dec. 31, 2018   185.4       (4.7)
Ending Balance at Dec. 31, 2018 5,864 $ 2 6,657 (464) (34) $ (297)
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Net income attributable to common shareholders 621     621    
Direct stock reinvestment and purchase plan (in shares)   0.0        
Direct stock reinvestment and purchase plan 7   7      
Employee stock purchase plan (in shares)   0.1        
Employee stock purchase plan 10   10      
Stock-based compensation activity (in shares)   0.4       (0.1)
Stock-based compensation activity $ 21   26 0   $ (5)
Repurchases of common stock (in shares) (0.4)         (0.3)
Repurchases of common stock $ (36)         $ (36)
Net other comprehensive income (2)       (2)  
Dividends (declared per common share) (362)     (362)    
Ending Balance (in shares) at Dec. 31, 2019   185.9       (5.1)
Ending Balance at Dec. 31, 2019 $ 6,121 $ 2 $ 6,700 $ (207) $ (36) $ (338)