PROPERTY AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property and equipment, net at December 31, 2021 and 2020 consist of the following (in millions):


	2021		2020		Estimated Useful Lives (years)
Computer equipment	$	728	$	746	2 to 6 years
Capitalized software	742		565		2 to 5 years
Leasehold improvements	268		278		1 to 15 years
Office equipment, furniture and fixtures	61		63		2 to 8 years

Building construction-in-progress	328		257
Total	2,127		1,909
Less: Accumulated depreciation	(1,305)		(1,153)
Property and equipment, net	$	822	$	756

Depreciation expense was $259 million, $291 million, and $294 million for the years ended December 31, 2021, 2020, and 2019, respectively. Additions to capitalized software during the years ended December 31, 2021, 2020, and 2019 were $191 million, $144 million, and $109 million, respectively.

Additional information related to Consolidated Statements of Cash Flows

Noncash investing activity related to additions to property and equipment, including stock-based compensation and accrued liabilities, was $51 million, $4 million, and $15 million for the years ended December 31, 2021, 2020, and 2019, respectively.