XML 202 R115.htm IDEA: XBRL DOCUMENT v3.20.4
Financial instruments - Reconciliation of changes in fair value (Details) - Level 3 [member] - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Disclosure of fair value measurement [line items]    
Opening balance $ 510 $ 485
Total gains and losses recognised in statement of income, assets 109 4
Purchases, assets 64 78
Settlement, assets (36) (52)
Transfer to level 1 1 (3)
Foreign currency translation differences 9 (3)
Closing balance 657 510
Non-current derivative financial instruments liabilities [Member]    
Disclosure of fair value measurement [line items]    
Opening balance (19) (35)
Total gains and losses recognised in statement of income, liabilities 14 16
Foreign currency translation differences 0  
Closing balance (5) (19)
Current derivative financial Instruments, liabilities [Member]    
Disclosure of fair value measurement [line items]    
Opening balance 0 (1)
Total gains and losses recognised in statement of income, liabilities 0 1
Foreign currency translation differences 0  
Closing balance 0 0
Non-current financial investments [Member]    
Disclosure of fair value measurement [line items]    
Opening balance 277 250
Total gains and losses recognised in statement of income, assets (29) (38)
Purchases, assets 64 78
Settlement, assets (8) (11)
Transfer to level 1 1 (3)
Foreign currency translation differences 4 0
Closing balance 308 277
Non-current derivative financial instruments - assets [Member]    
Disclosure of fair value measurement [line items]    
Opening balance 219 227
Total gains and losses recognised in statement of income, assets 106 (6)
Foreign currency translation differences 5 (2)
Closing balance 330 219
Current derivative financial instruments, assets [Member]    
Disclosure of fair value measurement [line items]    
Opening balance 33 44
Total gains and losses recognised in statement of income, assets 19 31
Purchases, assets   0
Settlement, assets (28) (42)
Transfer to level 1   0
Foreign currency translation differences 0 0
Closing balance $ 24 $ 33