4. Financial Statement Components

Accounts receivable, net consisted of the following (in thousands):



	December 31,
	2016			2015
Trade accounts receivable	$	12,640		$	9,554
Unbilled trade accounts receivable, net of advance client deposits	1,253			1,028
Allowance for doubtful accounts	(12		)	(15		)
Accounts receivable, net	$	13,881		$	10,567

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



	December 31,
	2016			2015
Computer and network equipment	$	37,664		$	30,277
Computer software	5,133			3,566
Internal-use software development costs	475			128
Furniture and fixtures	1,130			1,113
Leasehold improvements	624			619
Property and equipment	45,026			35,703
Accumulated depreciation and amortization	(30,338		)	(22,478		)
Property and equipment, net	$	14,688		$	13,225

Depreciation and amortization expense associated with property and equipment was $7.9 million, $6.9 million, and $6.0 million for the years ended December 31, 2016, 2015 and 2014, respectively.

Property and equipment capitalized under capital lease obligations consist primarily of computer and network equipment and were as follows (in thousands):



	December 31,
	2016			2015
Gross	$	35,504		$	27,302
Less: accumulated depreciation and amortization	(23,128		)	(16,429		)
Total	$	12,376		$	10,873

Accrued and other current liabilities consisted of the following (in thousands):



	December 31,
	2016		2015
Accrued expenses	$	2,148	$	2,193
Accrued compensation and benefits	7,456		5,718
Accrued and other current liabilities	$	9,604	$	7,911