XML 127 R110.htm IDEA: XBRL DOCUMENT v3.10.0.1
Debt - Schedule of Long-Term Debt (Details) - USD ($)
$ in Millions
Dec. 31, 2018
Dec. 31, 2017
Debt Instrument [Line Items]    
Long-term debt $ 6,301 $ 6,807
Less: amount due within one year 405 1
Long-term debt, excluding amount due within one year 5,896 6,806
5.72% Notes, due 2019    
Debt Instrument [Line Items]    
Long-term debt 0 500
1.63% Convertible Notes, due 2019    
Debt Instrument [Line Items]    
Long-term debt 403 403
6.150% Notes, due 2020    
Debt Instrument [Line Items]    
Long-term debt 1,000 1,000
5.40% Notes, due 2021    
Debt Instrument [Line Items]    
Long-term debt 1,250 1,250
5.87% Notes, due 2022    
Debt Instrument [Line Items]    
Long-term debt 627 627
5.125% Notes, due 2024    
Debt Instrument [Line Items]    
Long-term debt 1,250 1,250
5.90% Notes, due 2027    
Debt Instrument [Line Items]    
Long-term debt 625 625
6.75% Bonds, due 2028    
Debt Instrument [Line Items]    
Long-term debt 300 300
5.95% Notes due 2037    
Debt Instrument [Line Items]    
Long-term debt 625 625
Iowa Finance Authority Loan, due 2042 (4.75%)    
Debt Instrument [Line Items]    
Long-term debt 250 250
Other    
Debt Instrument [Line Items]    
Other $ (29) $ (23)