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)	2019			2018
Depreciation
Leasehold improvements	$	24		$	68
Asset retirement costs	(192		)	(76		)
Paging and computer equipment	1,666			1,855
Furniture, fixtures and vehicles	98			106
Total depreciation	1,596			1,953
Amortization	625			625
Accretion	138			135
Total depreciation, amortization and accretion expense	$	2,359		$	2,713

Accounts Receivable, Net

Accounts receivable was recorded net of an allowance of $1.5 million and $1.7 million at March 31, 2019 and December 31, 2018, respectively. Accounts receivable, net includes $3.4 million and $8.7 million of unbilled receivables at March 31, 2019 and December 31, 2018, 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. The decrease in unbilled receivables was primarily due to an increase in billings for the three months ended March 31, 2019.

Property and Equipment, Net

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



(Dollars in thousands)	Useful Life (In Years)	March 31, 2019			December 31, 2018
Leasehold improvements	shorter of useful life or lease term	$	3,708		$	4,139
Asset retirement costs	1-5	2,024			2,021
Paging and computer equipment	1-5	98,340			98,401
Furniture, fixtures and vehicles	3-5	4,358			4,353
Total property and equipment		108,430			108,914
Accumulated depreciation		(98,607		)	(98,560		)
Total property and equipment, net		$	9,823		$	10,354