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 September 30,						For the Nine Months Ended September 30,
(Dollars in thousands)	2019			2018			2019			2018
Depreciation
Leasehold improvements	$	14		$	60		$	50		$	195
Asset retirement costs	(191		)	(74		)	(575		)	(226		)
Paging and computer equipment	1,627			1,938			4,950			5,608
Furniture, fixtures and vehicles	92			100			285			310
Total depreciation	1,542			2,024			4,710			5,887
Amortization	625			625			1,875			1,875
Accretion	138			136			414			406
Total depreciation, amortization and accretion expense	$	2,305		$	2,785		$	6,999		$	8,168

Accounts Receivable, Net

Accounts receivable was recorded net of an allowance of $1.5 million and $1.7 million at September 30, 2019 and December 31, 2018, respectively. Accounts receivable, net includes $5.8 million and $8.7 million of unbilled receivables at September 30, 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 nine months ended September 30, 2019.

Property and Equipment, Net

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



(Dollars in thousands)	Useful Life (In Years)	September 30, 2019			December 31, 2018
Leasehold improvements	shorter of useful life or lease term	$	3,624		$	4,139
Asset retirement costs	1-5	2,041			2,021
Paging and computer equipment	1-5	98,403			98,401
Furniture, fixtures and vehicles	3-5	3,639			4,353
Total property and equipment		107,707			108,914
Accumulated depreciation		(98,104		)	(98,560		)
Total property and equipment, net		$	9,603		$	10,354