Property and Equipment

12 Months Ended

Dec. 31, 2015

Property and Equipment

Property and Equipment

4.Property and Equipment

Property and equipment consists of the following:

			At December 31,
	Estimated Useful Life		2015		2014
Cost:
Computer equipment and software	3	years	$	44,470	$	18,540
Office furniture and fixtures	7	years		5,785		4,993
Leasehold improvements	Shorter of the lease term or useful life of the asset			15,123		10,805
Other office equipment	5	years		683		144
				66,061		34,482
Less accumulated depreciation and amortization				(37,380)		(17,853)
Property and equipment, net			$	28,681	$	16,629

During 2015, the Company retired fully depreciated property and equipment that were no longer in service in the amount of $5,944. See below for the cost amounts and related accumulated depreciation written off by category:

			Accumulated
	Cost		Depreciation
Computer equipment and software	$	5,749	$	(5,749)
Office furniture and fixtures		106		(106)
Other office equipment		68		(68)
Leasehold improvements		21		(21)
Total property and equipment retirements	$	5,944	$	(5,944)

During 2014, the Company retired fully depreciated property and equipment that were no longer in service in the amount of $18,207. See below for the cost amounts and related accumulated depreciation written off by category:

			Accumulated
	Cost		Depreciation
Computer equipment and software	$	15,455	$	(15,455)
Leasehold improvements		1,435		(1,435)
Office furniture and fixtures		721		(721)
Other office equipment		596		(596)
Total property and equipment retirements	$	18,207	$	(18,207)

Depreciation and amortization expense was as follows:

	Year Ended December 31,
	2015		2014		2013
Depreciation and amortization expense	$	7,668	$	5,910	$	5,151