Financial Statement Components

Cash and cash equivalents consisted of the following (in thousands):



	June 30, 2018		December 31, 2017
Cash	$	54,242	$	48,855
Commercial paper	500		—
Money market funds	75,765		20,092
Certificates of deposit	498		—
U.S. agency securities	35,157		—
Cash and cash equivalents	$	166,162	$	68,947

As of June 30, 2018, the Company was required to maintain $25.0 million of unrestricted cash and cash equivalents deposited with two lenders in connection with its credit agreement as a compensating balance. The credit agreement was terminated on July 1, 2018. See Note 6.

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



	June 30, 2018			December 31, 2017
Trade accounts receivable	$	19,378		$	17,481
Unbilled trade accounts receivable, net of advance client deposits	817			1,600
Allowance for doubtful accounts	(28		)	(33		)
Accounts receivable, net	$	20,167		$	19,048

Prepaid expenses and other current assets consisted of the following (in thousands):



	June 30, 2018		December 31, 2017
Prepaid expenses	$	5,394	$	2,437
Other current assets	2,052		2,403
Contract assets	991		—
Prepaid expenses and other current assets	$	8,437	$	4,840

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



	June 30, 2018			December 31, 2017
Computer and network equipment	$	47,933		$	47,195
Computer software	7,571			6,974
Internal-use software development costs	500			500
Furniture and fixtures	1,458			1,282
Leasehold improvements	797			801
Property and equipment	58,259			56,752
Accumulated depreciation and amortization	(36,240		)	(36,864		)
Property and equipment, net	$	22,019		$	19,888

Depreciation and amortization expense associated with property and equipment was $2.3 million and $4.5 million for the three and six months ended June 30, 2018, respectively, and $2.2 million and $4.1 million for the three and six months ended June 30, 2017, respectively.

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



	June 30, 2018			December 31, 2017
Gross	$	48,020		$	46,624
Less: accumulated depreciation and amortization	(30,034		)	(30,438		)
Total	$	17,986		$	16,186

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



	June 30, 2018		December 31, 2017
Accrued compensation and benefits	$	9,945	$	8,657
Accrued expenses	3,670		3,130
Accrued and other current liabilities	$	13,615	$	11,787