XML 152 R121.htm IDEA: XBRL DOCUMENT v3.20.4
Leases - Maturity Analysis of Undiscounted Cash Out Flows (Details) - USD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Finance leases    
2021 $ 106  
2022 90  
2023 62  
2024 33  
2025 16  
Thereafter 36  
Imputed Interest (47)  
Finance lease obligations 296 $ 204
Operating leases    
2021 1,468  
2022 1,186  
2023 885  
2024 683  
2025 405  
Thereafter 638  
Imputed Interest (334)  
Operating lease liabilities 4,930  
Amount of leases not yet commenced $ 376