v3.22.0.1
Summary of Significant Accounting Policies - Narrative (Details)
 3 Months Ended 12 Months Ended
Dec. 31, 2021
USD ($)
Dec. 31, 2021
USD ($)
reporting_unit
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Sep. 30, 2021
USD ($)
Jan. 01, 2019
USD ($)
Goodwill [Line Items]            
Number of reporting units | reporting_unit   3        
Carrying value of goodwill $ 322,000,000 $ 322,000,000 $ 390,000,000 $ 386,000,000    
Maximum period between quantitative goodwill impairment tests   3 years        
Goodwill impairment   $ 65,000,000 0 0    
Accumulated impairment losses $ 93,000,000 93,000,000 28,000,000 28,000,000    
Goodwill and Intangible Asset Impairment   65,000,000 0 0    
Weighted Average Cost of Capital, Basis Points 15000.00%          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]            
Operating lease right-of-use assets $ 122,000,000 122,000,000 144,000,000     $ 150,000,000
Operating lease liabilities 125,000,000 125,000,000       $ 150,000,000
Reclassification from other noncurrent liabilities and deferred credits (85,000,000) (85,000,000) (102,000,000)      
Reclassification from properties, plants, and equipment, net (2,651,000,000) (2,651,000,000) (2,712,000,000)      
Reclassification from deferred income tax assets (229,000,000) (229,000,000) (329,000,000)      
Rolled Products            
Goodwill [Line Items]            
Carrying value of goodwill 253,000,000 253,000,000 254,000,000 246,000,000 $ 254,000,000  
Goodwill impairment   0        
Accumulated impairment losses 0 0 0 0    
Building and Construction Systems            
Goodwill [Line Items]            
Carrying value of goodwill 69,000,000 69,000,000 71,000,000 69,000,000 70,000,000  
Goodwill impairment   0        
Accumulated impairment losses 28,000,000 28,000,000 28,000,000 28,000,000    
Extrusions            
Goodwill [Line Items]            
Carrying value of goodwill 0 0 65,000,000 71,000,000 $ 65,000,000  
Goodwill impairment   65,000,000        
Accumulated impairment losses $ 65,000,000 65,000,000 $ 0 0    
Rolled Products and Building and Construction Systems            
Goodwill [Line Items]            
Goodwill impairment   $ 0        
Adoption of accounting standard            
New Accounting Pronouncements or Change in Accounting Principle [Line Items]            
Reclassification to Parent Company net investment       73,000,000    
Reclassification from other noncurrent liabilities and deferred credits       119,000,000    
Reclassification from properties, plants, and equipment, net       24,000,000    
Reclassification from deferred income tax assets       $ 22,000,000