Property, Plant, and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property, Plant and Equipment [Abstract]

Property, plant, and equipment

Property, plant, and equipment were composed of the following:

	December 31
Millions of dollars	2014		2013
Land	$	217	$	213
Buildings and property improvements	3,311		2,685
Machinery, equipment, and other	19,954		17,904
Total	23,482		20,802
Less accumulated depreciation	11,007		9,480
Net property, plant, and equipment	$	12,475	$	11,322

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
	2014	2013
1    -   10 years	12%	13%
11    -   20 years	42%	43%
21    -   30 years	21%	20%
31    -   40 years	25%	24%

	Machinery, Equipment, and Other
	2014	2013
1    -    5 years	23%	22%
6    -   10 years	70%	72%
11    -   20 years	7%	6%