PROPERTY AND EQUIPMENT, NET

12 Months Ended

Dec. 31, 2023

Property, Plant and Equipment [Abstract]

Property and equipment are stated at cost, net of accumulated depreciation and amortization. The costs of additions and improvements are capitalized, while maintenance and repairs are charged to expense as incurred. When an item is sold or retired, the cost and related accumulated depreciation are relieved, and the resulting gain or loss, if any, is recognized in the consolidated statements of income. We evaluate our property and equipment for impairment periodically or as changes in circumstances or the occurrence of events suggest the remaining value is not recoverable from future cash flows. If the carrying value of our property and equipment is impaired, an impairment charge is recorded for the amount by which the carrying value of the property and equipment exceeds its fair value. We provide for depreciation and amortization primarily using the straight-line method by charges to the consolidated statements of income in amounts that allocate the cost of property and equipment over their estimated useful lives as follows:


Asset Classification						Estimated Useful Life

Buildings and improvements						10 to 40 years
Leasehold improvements						Shorter of remaining lease term or useful life of improvements
Machinery and equipment						3 to 8 years
Office furniture and equipment						3 to 7 years
Computer hardware and software						3 to 7 years

We capitalize interest on the acquisition and construction of significant assets that require a substantial period of time to be made ready for use. The capitalized interest is included in the cost of the completed asset and depreciated over the asset’s estimated useful life. The amount of interest capitalized during the years ended December 31, 2023 and 2022, was not material.

We capitalize certain costs incurred in connection with developing or obtaining software designated for internal use based on three distinct stages of development. Qualifying costs incurred during the application development stage, which consist primarily of internal payroll and direct fringe benefits and external direct project costs, including labor and travel, are capitalized and amortized on a straight-line basis over the estimated useful life of the asset. Costs incurred during the preliminary project and post-implementation and operation phases are expensed as incurred. These costs relate primarily to the determination of performance requirements, data conversion, and training. Software developed to deliver hosted services to our customers has been designated as internal use.

Property and equipment, net, consisted of the following:


(in thousands)	December 31, 2023		December 31, 2022

Land and improvements	$	22,400	$	22,221
Buildings and improvements	432,038		356,049
Leasehold improvements	116,347		107,251
Machinery and equipment	431,914		404,963
Office furniture and equipment	78,941		71,625
Computer hardware and software	326,295		295,969
Construction in progress	79,059		97,310
	1,486,994		1,355,388
Less accumulated depreciation and amortization	784,817		705,914
Total property and equipment, net	$	702,177	$	649,474

Below are the amounts of depreciation and amortization of property and equipment, capitalized computer software for internal use, unpaid property and equipment reflected in accounts payable and accrued expenses, and rental and reagent rental program instruments transferred from inventory to property and equipment:


	For the Years Ended December 31,
(in thousands)	2023		2022		2021

Depreciation and amortization expense	$	100,994	$	96,746	$	92,376
Capitalization of internal-use software development costs during the period	$	37,120	$	20,329	$	14,753
Unpaid property and equipment, reflected in accounts payable and accrued liabilities at end of year	$	12,061	$	18,334	$	19,326
Rental and operating-type reagent rental program instruments transferred from inventory to property and equipment during the period (Note 3)	$	14,608	$	17,407	$	11,628

We had no material impairments of fixed assets for the years ended December 31, 2023 and 2022. We had impairments of $5.1 million for the year ended December 31, 2021, associated with a write-down of rental assets in certain regions.