Fixed Assets

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

FIXED ASSETS, NETFixed assets, net, are stated at cost less accumulated depreciation. Major improvements are capitalized while expenditures for maintenance, repairs and minor improvements are expensed. For sales or asset retirements, the assets and related accumulated

depreciation and amortization are eliminated from the accounts. Gains and losses on sales of our fixed assets, net, are generally recorded in operating income; however, for our RIS and RMD segments, gains and losses that are allocable to our contracts are included in overhead, as we are required to allocate gains or losses and generally can recover these costs through the pricing of products and services to the U.S. government.


(dollars in millions)	Estimated Useful Lives	2020		2019
Land		$	773	$	292
Buildings and improvements	12-45 years	7,067		4,978
Machinery, tools and equipment	3-20 years	15,994		12,936
Other, including assets under construction		2,512		1,871
		26,346		20,077
Accumulated depreciation		(11,384)		(9,755)
		$	14,962	$	10,322

Leasehold improvements are amortized over the lesser of the remaining lease term or the estimated useful life of the improvement.

Depreciation expense related to fixed assets, net is recorded predominantly utilizing the straight-line method and was $1,767 million in 2020, $1,191 million in 2019 and $945 million in 2018.