CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 332,764	$ 547,850
Short-term marketable securities	423,096	273,366
Accounts receivable (net of allowance for doubtful accounts of $8,685 and $8,602 at December 31, 2018 and December 31, 2017, respectively)	87,305	76,173
Prepaid expenses and other current assets	17,104	15,700
Total current assets	860,269	913,089
Long-term marketable securities	0	25,032
Property, equipment and software, net	114,800	103,651
Goodwill	105,620	107,954
Intangibles, net	13,359	16,893
Restricted cash	22,071	18,554
Other non-current assets	59,444	40,428
Total assets	1,175,563	1,225,601
Current liabilities:
Accounts payable	6,540	9,033
Accrued liabilities	54,522	73,665
Deferred revenue	3,843	3,469
Total current liabilities	64,905	86,167
Long-term liabilities	35,140	30,737
Total liabilities	100,045	116,904
Commitments and contingencies (Note 12)
Stockholders’ equity:
Common stock, $0.000001 par value — 200,000,000 shares authorized, 81,996,839 and 83,724,916 shares issued and outstanding at December 31, 2018 and December 31, 2017, respectively	0	0
Additional paid-in capital	1,139,462	1,038,017
Treasury stock	0	(46)
Accumulated other comprehensive loss	(11,021)	(8,444)
(Accumulated deficit) retained earnings	(52,923)	79,170
Total stockholders’ equity	1,075,518	1,108,697
Total liabilities and stockholders’ equity	$ 1,175,563	$ 1,225,601