XML 89 R80.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Valuation and Qualifying Accounts (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]      
Accounts Receivable, Allowance for Credit Loss, Current $ 1    
Valuation and Qualifying Accounts      
Balance at beginning of period 40 $ 16 $ 17
Additions Charged to Costs and Expenses 14 26 3
Deductions 0 2 4
Balance at end of period 54 40 16
Allowance for doubtful accounts [Member]      
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]      
Accounts Receivable, Allowance for Credit Loss, Current   1  
Valuation and Qualifying Accounts      
Balance at beginning of period 1 1 5
Additions Charged to Costs and Expenses 0 2 0
Deductions 0 2 4
Balance at end of period 1 1 1
Allowance for obsolete inventory parts [Member]      
Valuation and Qualifying Accounts      
Balance at beginning of period 18 14 12
Additions Charged to Costs and Expenses 4 4 2
Deductions 0 0 0
Balance at end of period 22 18 14
Valuation allowance for deferred tax assets [Member]      
Valuation and Qualifying Accounts      
Balance at beginning of period 21 1 0
Additions Charged to Costs and Expenses 10 20 1
Deductions 0 0 0
Balance at end of period $ 31 $ 21 $ 1