XML 38 R90.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Commitments and Contingencies Purchase Obligations and Operating Lease Commitment Tables (Details) - Energy Segment - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Unconditional purchase obligations      
2019 $ 95    
2020 80    
2021 77    
2022 75    
2023 71    
Thereafter 375    
Minimum required payments for unconditional purchase obligations 773    
Amounts purchased under supply agreements $ 167 $ 214 $ 209