Property and Equipment

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and Equipment

Property and equipment consisted of the following (in millions):

	As of December 31,						Depreciation Period (Years)
	2019			2018
Software and internally developed software	$	1,056		$	919		3 to 7
Computer and network equipment	742			682			3 to 5
Land	146			145			N/A
Buildings and building improvements	309			294			15 to 40
Right-of-use lease assets	287			—			1 to 16
Leasehold improvements	269			242			4 to 12
Equipment, aircraft and office furniture	233			225			4 to 15
	3,042			2,507
Less accumulated depreciation and amortization	(1,506		)	(1,266		)
Property and equipment, net	$	1,536		$	1,241

Beginning January 1, 2019, in connection with our adoption of ASU 2016-02 (Note 2), we recognize right-of-use assets representing our rights to use assets over an underlying lease term as rent expense.

In 2019, 2018 and 2017, amortization of software and internally developed software was $175 million, $160 million and $135 million, respectively, and depreciation of all other property and equipment was $145 million, $133 million and $122 million, respectively. As of December 31, 2019 and 2018, unamortized software and internally developed software was $301 million and $298 million, respectively.