Description of Business and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Allowance for Doubtful Accounts

The following table presents the changes in the allowance for doubtful accounts (in thousands):



	Year Ended December 31,
	2017			2016			2015
Balance, beginning of period	$	12		$	15		$	65
Add: bad debt expense	95			75			171
Less: write-offs, net of recoveries	(74		)	(78		)	(221		)
Balance, end of period	$	33		$	12		$	15

Schedule of Property and Equipment, Useful Lives

Property and equipment is stated at cost less accumulated depreciation and amortization, and is depreciated using the straight-line method over the estimated useful lives of the assets as follows:



Asset Category		Estimated Useful Lives
Computer and network equipment		3 to 5 years
Computer software		3 years
Development costs		1 to 5 years
Furniture and fixtures		7 years
Leasehold improvements		Shorter of useful life or lease term

Property and equipment, net consisted of the following (in thousands):



	December 31,
	2017			2016
Computer and network equipment	$	47,195		$	37,664
Computer software	6,974			5,133
Internal-use software development costs	500			475
Furniture and fixtures	1,282			1,130
Leasehold improvements	801			624
Property and equipment	56,752			45,026
Accumulated depreciation and amortization	(36,864		)	(30,338		)
Property and equipment, net	$	19,888		$	14,688