Property, Plant, and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Property, plant, and equipment

Property, plant and equipment were composed of the following:

	December 31
Millions of dollars	2016		2015
Land	$	228	$	240
Buildings and property improvements	3,399		3,486
Machinery, equipment and other	16,103		19,967
Total	19,730		23,693
Less accumulated depreciation	11,198		11,576
Net property, plant and equipment	$	8,532	$	12,117

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, excluding oil and natural gas investments, are depreciated over the following useful lives:

	Buildings and Property Improvements
	2016	2015
1    -   10 years	11%	12%
11    -   20 years	42%	41%
21    -   30 years	22%	22%
31    -   40 years	25%	25%

	Machinery, Equipment and Other
	2016	2015
1    -    5 years	34%	23%
6    -   10 years	57%	69%
11    -   20 years	9%	8%