Net Property, Plant and Equipment (Tables)

12 Months Ended

Dec. 31, 2017

Net Property, Plant and Equipment

Summary of property, plant and equipment

	Useful				December 31,
(Millions of dollars)	Lives				2017		2016
Land and improvements	3	-	15	years	$	224	$	214
Buildings and improvements			30	years		525		486
Machinery and equipment	3	-	20	years		1,253		1,142
Vessels and vehicles	3	-	18	years		136		140
Office furniture and fixtures			5	years		34		32
Construction in progress						56		58
						2,228		2,072
Accumulated depreciation and amortization						(1,151)		(1,066)
Net property, plant and equipment					$	1,077	$	1,006