FIXED ASSETS

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Fixed assets, net, summarized by major category, consist of the following (in thousands):


	December 31,
	2021		2020
Machinery and equipment	$	117,264	$	74,966
Leasehold improvements	59,740		54,434
Computer equipment and software	13,197		12,170
Office furniture and equipment	2,883		2,387
Construction in progress	80,557		71,091
Total	273,641		215,048
Less: accumulated depreciation	(85,240)		(78,360)
Fixed assets, net	$	188,401	$	136,688

For information on useful lives by asset category, refer to Note 2, Summary of Significant Accounting Policies.

Depreciation expense for the years ended December 31, 2021, 2020 and 2019 was $15.0 million, $12.0 million and $14.0 million, respectively. During the years ended December 31, 2021, 2020 and 2019, the Company capitalized interest of $3.9 million, $2.4 million and less than $0.1 million, respectively.

As of December 31, 2021 and 2020, total fixed assets, net, includes leasehold improvements and manufacturing process equipment located outside of the U.S. in the amount of $65.4 million and $67.5 million, respectively.

As of December 31, 2021 and 2020, the Company had AROs of $2.4 million and $2.0 million, respectively, included in accrued expenses and other liabilities on its consolidated balance sheet, for costs associated with returning leased space to its original condition upon the termination of certain lease agreements.