Property and equipment consisted of the following:


	September 30,			December 31,
	2024			2023
Building and leasehold improvements	$	75,630		$	65,762
Internal use software		11,202			4,625
Furniture, computers and equipment		57,596			59,960
		144,428			130,347
Accumulated depreciation and amortization		(75,166	)		(73,186	)
Construction in progress		20,606			59,067
Total	$	89,868		$	116,228

Depreciation and amortization expense was $3,570, $10,008, $2,544, and $7,466 for the three and nine months ended September 30, 2024 and 2023, respectively.

During the second quarter of 2024, the Company placed certain modules of its enterprise resource planning (ERP) system into service, the costs of which had previously been capitalized as construction in progress and will be expensed over their anticipated useful life, currently estimated to be five years. At such time, the Company determined that certain other modules within the ERP system and other internal-use software had no future use, and accordingly the Company recorded a write down of $3,959 of costs related to this internal-use software.

During the second quarter of 2024, the Company decided to pursue the potential sale of a purchased building, located on the Company’s Canton, Massachusetts campus, on which it had previously paused construction work. The Company identified this change in expectation regarding the use of the building as an impairment indicator. The Company determined the asset group to be comprised of the building and associated construction, and performed the impairment assessment at the asset group level. The Company determined the impairment charge by comparing the fair value of the asset group to its book value and recorded an impairment charge of $18,842 related to the building and associated unfinished construction work, allocated to each asset class within the asset group based on its relative carrying value. See Note 14, Fair Value Measurements.

During the second quarter of 2024, the Company determined that the factors above constituted an impairment trigger relating to its remaining company-wide asset group. The Company performed a recoverability test in accordance with ASC 360, Property, Plant and Equipment. The estimated undiscounted cash flows directly attributable to the asset group exceeded its carrying value, and accordingly the Company did not record any impairment related to this asset group. The Company did not record any impairment relating to its long-lived asset groups during the three months ended September 30, 2024.