Fixed Assets

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Fixed Assets

FIXED ASSETS

(dollars in millions)	Estimated Useful Lives	2016			2015
Land		$	392		$	384
Buildings and improvements	12-40 years	5,180			5,030
Machinery, tools and equipment	3-20 years	12,471			11,717
Other, including assets under construction		1,426			1,363
		19,469			18,494
Accumulated depreciation		(10,311		)	(9,762		)
		$	9,158		$	8,732

Depreciation expense was $1,105 million in 2016, $1,068 million in 2015 and $1,043 million in 2014.