Acquisitions - Purchase Price Allocation (Details) - USD ($)
$ in Millions
Mar. 01, 2017
Feb. 01, 2017
Mar. 31, 2018
Dec. 31, 2017
Business Acquisition [Line Items]        
Business Combination, Goodwill     $ 130 $ 127
USM - Warren [Member]        
Business Acquisition [Line Items]        
Total purchase consideration $ 78      
Business Combination, Accounts receivable - Trade 17      
Business Combination, Accounts receivable - Other 3      
Business Combination, Inventories 9      
Business Combination, Goodwill 3      
Business Combination, Intangibles 33      
Business Combination, Property, plant and equipment 50      
Business Combination, Accounts payable (34)      
Business Combination, Accrued payroll and employee benefits (2)      
Business Combination, Other accrued liabilities (1)      
Business Combination, Total purchase consideration allocation $ 78      
BFP and BPT [Member]        
Business Acquisition [Line Items]        
Total purchase consideration   $ 172    
Business Combination, Cash and cash equivalents   75    
Business Combination, Accounts receivable - Trade   78    
Business Combination, Accounts receivable - Other   18    
Business Combination, Inventories   134    
Business Combination, Other current assets   9    
Business Combination, Goodwill   20    
Business Combination, Intangibles   41    
Business Combination, Deferred tax assets   3    
Business Combination, Other noncurrent assets   4    
Business Combination, Property, plant and equipment   145    
Business Combination, Notes payable, including current portion of long-term debt   (130)    
Business Combination, Accounts payable   (51)    
Business Combination, Accrued payroll and employee benefits   (14)    
Business Combination, Taxes on income   (1)    
Business Combination, Other accrued liabilities   (19)    
Business Combination, Long-term debt   (51)    
Business Combination, Pension and postretirement obligations   (11)    
Business Combination, Other noncurrent liabilities   (22)    
Business Combination, Redeemable noncontrolling interest   (44)    
Business Combination, Noncontrolling interests   (12)    
Business Combination, Total purchase consideration allocation   $ 172