Accounting policies (Tables)

12 Months Ended

Dec. 31, 2019

Disclosure of initial application of standards or interpretations [abstract]

Schedule of useful lives of property, plant and equipment

	Years of
	Estimated
	Useful
	Life
Properties for own use	25-50
Plant and machinery	8-20
Tools	12.5-15
Furniture and fixtures	10-15
Computer hardware	4-8
Transport equipment	10-15