Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 88,888	$ 80,452
Marketable securities	0	7,524
Accounts receivable, net	217,571	205,683
Prepaid expenses and other current assets	6,591	6,882
TOTAL CURRENT ASSETS	313,050	300,541
Property and equipment, net	23,667	33,487
Right of use lease asset	21,491
Internal use software development costs, net	16,053	14,570
Intangible assets, net	11,386	10,174
Goodwill	7,370	0
Other assets, non-current	2,103	1,240
TOTAL ASSETS	395,120	360,012
Current liabilities:
Accounts payable and accrued expenses	259,439	239,678
Lease liabilities - current portion	7,282
Other current liabilities	778	1,304
TOTAL CURRENT LIABILITIES	267,499	240,982
Lease liabilities - non-current portion	15,231
Other liabilities, non-current	454	1,017
TOTAL LIABILITIES	283,184	241,999
Commitments and contingencies (Note 17)
STOCKHOLDERS' EQUITY
Preferred stock, $0.00001 par value, 10,000 shares authorized at December 31, 2019 and December 31, 2018; 0 shares issued and outstanding at December 31, 2019 and December 31, 2018	0	0
Common stock, $0.00001 par value; 500,000 shares authorized at December 31, 2019 and December 31, 2018; 53,888 and 51,159 shares issued, and outstanding at December 31, 2019 and December 31, 2018, respectively	1	1
Additional paid-in capital	453,064	433,877
Accumulated other comprehensive loss	(45)	(259)
Accumulated deficit	(341,084)	(315,606)
TOTAL STOCKHOLDERS' EQUITY	111,936	118,013
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 395,120	$ 360,012