XML 200 R173.htm IDEA: XBRL DOCUMENT v3.21.1
Employee benefits - Costs recognized in the income statement (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Overfunded pension plans      
Costs recognized in the income statement      
Service cost $ 7 $ 7 $ 5
Interest on expense on liabilities 222 317 282
Interest income on plan assets (297) (432) (406)
Interest expense on effect of (asset ceiling)/ onerous liability 74 114 124
Total of cost, net 6 6 5
Underfunded pension plans      
Costs recognized in the income statement      
Service cost 52 55 101
Interest on expense on liabilities 134 153 158
Interest income on plan assets (107) (123) (127)
Total of cost, net 79 85 132
Other benefits      
Costs recognized in the income statement      
Service cost 18 10 36
Interest on expense on liabilities 64 57 59
Total of cost, net $ 82 $ 67 $ 95