Property and Equipment

9 Months Ended

Sep. 30, 2021

Property Plant And Equipment [Abstract]

4.	PROPERTY AND EQUIPMENT

Property and equipment and accumulated depreciation and amortization were as follows:

	September 30, 2021			December 31, 2020
Property and equipment
Software and capitalized software costs	$	184,196		$	144,190
Buildings		116,045			115,772
Computer equipment		78,710			68,181
Rental clocks		28,928			25,474
Furniture, fixtures and equipment		21,269			19,829
Other		7,451			7,016
		436,599			380,462
Less: accumulated depreciation and amortization		(224,713	)		(178,111	)
		211,886			202,351
Construction in progress		88,376			53,833
Land		29,034			29,034
Property and equipment, net	$	329,296		$	285,218

We capitalize computer software development costs related to software developed for internal use in accordance with ASC 350-40. For the three and nine months ended September 30, 2021, we capitalized $13.2 million and $39.2 million, respectively, of computer software development costs related to software developed for internal use. For the three and nine months ended September 30, 2020, we capitalized $11.7 million and $32.4 million, respectively, of computer software development costs related to software developed for internal use.

Rental clocks included in property and equipment, net represent time clocks issued to clients under month-to-month operating leases. As such, these items are transferred from inventory to property and equipment and depreciated over their estimated useful lives.

We capitalize interest incurred for indebtedness related to construction in progress. For the three and nine months ended September 30, 2021, we incurred interest costs of $0.4 million and $1.1 million, respectively, of which we capitalized $0.4 million and $1.1 million, respectively. For the three and nine months ended September 30, 2020, we incurred interest costs of $0.4 million and $1.1 million, respectively, of which we capitalized $0.4 million and $1.1 million, respectively. Included in the construction in progress balance at September 30, 2021 and December 31, 2020 is $3.4 million and $3.5 million in retainage, respectively.

Depreciation and amortization expense for property and equipment was $16.3 million and $46.8 million, respectively, for the three and nine months ended September 30, 2021. Depreciation and amortization expense for property and equipment was $13.8 million and $39.1 million, respectively, for the three and nine months ended September 30, 2020.