CONSOLIDATED FINANCIAL STATEMENT COMPONENTS

Depreciation, Amortization and Accretion

Depreciation, amortization and accretion expenses consisted of the following for the periods stated:



	For the Three Months Ended March 31,
(Dollars in thousands)	2020			2019
Depreciation
Leasehold improvements	$	16		$	24
Asset retirement costs	(161		)	(192		)
Paging and computer equipment	1,478			1,666
Furniture, fixtures and vehicles	70			98
Total depreciation	1,403			1,596
Amortization	625			625
Accretion	118			138
Total depreciation, amortization and accretion expense	$	2,146		$	2,359

Accounts Receivable, Net

Accounts receivable was recorded net of an allowance of $1.6 million and $1.3 million at March 31, 2020 and December 31, 2019, respectively. Accounts receivable, net includes $6.5 million and $6.4 million of unbilled receivables at March 31, 2020 and December 31, 2019, respectively. Unbilled receivables are defined as the Company's right to consideration in exchange for goods or services that we have transferred to the customer but have not yet billed for, generally as a result of contractual billing terms.

Property and Equipment, Net

Property and equipment, net consisted of the following as of the dates stated:



(Dollars in thousands)	Useful Life (In Years)	March 31, 2020			December 31, 2019
Leasehold improvements	shorter of useful life or lease term	$	3,620		$	3,620
Asset retirement costs	1-5	1,922			1,922
Paging and computer equipment	1-5	95,542			96,562
Furniture, fixtures and vehicles	3-5	3,585			3,716
Total property and equipment		104,669			105,820
Accumulated depreciation		(97,014		)	(97,820		)
Total property and equipment, net		$	7,655		$	8,000

Capitalized Software Development

Capitalized software development is amortized on a straight-line basis over the estimated useful life of the asset, typically three years. Capitalized software development costs were $1.7 million for the three months ended March 31, 2020 and no capitalized costs were recorded for the three months ended March 31, 2019. There was no amortization expense with respect to software development costs for the three months ended March 31, 2020 and 2019.