Property and Equipment

12 Months Ended

Dec. 31, 2021

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and equipment

Property and equipment were comprised of the following:

	December 31,
	2021		2020
Land	$	34,009	$	37,924
Buildings	496,455		400,616
Leasehold improvements	3,828,404		3,865,729
Equipment and information systems, including internally developed software	3,292,176		3,081,298
New center and capital asset projects in progress	592,063		616,686
	8,243,107		8,002,253
Less accumulated depreciation	(4,763,135)		(4,480,429)
	$	3,479,972	$	3,521,824

Depreciation and amortization expenses are computed using the straight-line method over the useful lives of the assets estimated as follows: buildings, 25 years to 40 years; leasehold improvements, the shorter of ten years or the expected lease term; and equipment and information systems, including internally developed software, principally three years to 15 years.

Depreciation expense on property and equipment was $667,755, $616,626, and $600,905 for 2021, 2020 and 2019, respectively.

Interest on debt incurred during the development of new centers and other capital asset projects is capitalized as a component of the asset cost based on the respective in-process capital asset balances. Interest capitalized was $15,275, $17,944 and $27,322 for 2021, 2020 and 2019, respectively.