Production and similar taxes

6 Months Ended

Jun. 30, 2018

Analysis of income and expense [abstract]

Production and similar taxes

Production and similar taxes

	Second	Second	First	First
	quarter	quarter	half	half
$ million	2018	2017	2018	2017
US	89	41	179	77
Non-US	442	306	720	738
	531	347	899	815