Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Summary of Estimated Useful Life of Property, Plant and Equipment

The depreciation of other assets that do not qualify as “Major equipment” is calculated under the straight-line method to allocate their cost less their residual values over their estimated useful lives, as follows:

	Years
Buildings and facilities		Between 3 and 50
Machinery and equipment		Between 4 and 10
Vehicles		Between 2 and 10
Furniture and fixtures		Between 2 and 10
Other equipment		Between 2 and 10