Property, Plant, and Equipment (Tables)

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Property, plant, and equipment

Property, plant and equipment were composed of the following:

	December 31
Millions of dollars	2019		2018
Land	$	202	$	252
Buildings and property improvements	3,167		3,461
Machinery, equipment and other	16,571		18,313
Total	19,940		22,026
Less accumulated depreciation	12,630		13,153
Net property, plant and equipment	$	7,310	$	8,873

Percentages of building and property improvements, and total machinery, and equipment and other, excluding oil and natural gas investments, depreciated over useful lives

Classes of assets are depreciated over the following useful lives:

	Buildings and Property Improvements
	2019	2018
1    -   10 years	12%	11%
11    -   20 years	41%	42%
21    -   30 years	22%	22%
31    -   40 years	25%	25%

	Machinery, Equipment and Other
	2019	2018
1    -    5 years	43%	34%
6    -   10 years	47%	56%
11    -   20 years	10%	10%