XML 55 R46.htm IDEA: XBRL DOCUMENT v3.10.0.1
Financial instruments disclosures - Summary of changes in fair value of Level 3 financial assets and financial liabilities (Detail) - Level 3 [member] - USD ($)
$ in Millions
 6 Months Ended 12 Months Ended
Jun. 30, 2018
Dec. 31, 2017
Disclosure Of Financial Instruments [Line Items]    
Opening balance $ (7) $ 479
Adjustment from transition 19  
Currency translation adjustments (9) 8
– Consolidated sales revenue 0 1
– Net operating costs (1) (5)
– Consolidated sales revenue (6) 17
– Net operating costs 145 (508)
Total unrealised gains transferred into other comprehensive income 93  
Disposals/maturity of financial instruments   (5)
Transfers 22 6
Closing balance 256 (7)
Total gains/(losses) included in the income statement for assets and liabilities held at end of period $ 138 $ (491)