Property and Equipment

12 Months Ended

Dec. 31, 2020

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and Equipment

Property and equipment consisted of the following as of December 31, 2020 and 2019 (in thousands except years):

	December 31, 2020		December 31, 2019		Estimated Useful Life (in years)
Computer and networking equipment	$	1,847,717	$	1,469,293	3-7
Purchased software	95,662		90,450		3-10
Furniture and fixtures	71,119		65,683		1-7
Office equipment	40,235		38,178		3-5
Leasehold improvements	230,423		235,279		1-15
Internal-use software	1,234,934		1,132,180		2-7
Property and equipment, gross	3,520,090		3,031,063
Accumulated depreciation and amortization	(2,041,818)		(1,878,910)
Property and equipment, net	$	1,478,272	$	1,152,153

Depreciation and amortization expense on property and equipment and capitalized internal-use software for the years ended December 31, 2020, 2019 and 2018 was $436.3 million, $402.1 million and $401.2 million, respectively. During the years ended December 31, 2020, 2019 and 2018, the Company capitalized $38.0 million, $35.9 million and $34.8 million, respectively, of stock-based compensation related to employees who developed and enhanced internal-use software applications.

During the years ended December 31, 2020 and 2019, the Company wrote off $279.9 million and $166.7 million, respectively, of property and equipment, gross, along with the associated accumulated depreciation and amortization. The write-

offs were primarily related to leasehold improvements, computer and networking equipment and internal-use software no longer in use. These assets had been substantially depreciated and amortized. In addition, the Company wrote off $0.8 million and $3.8 million, primarily of internal-use software as a result of certain restructuring efforts during the year ended December 31, 2020 and December 31, 2019, respectively.