CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	[1]
Current assets:
Cash and cash equivalents	$ 423,495	$ 547,850
Short-term marketable securities	414,002	273,366
Accounts receivable (net of allowance for doubtful accounts of $8,885 and $8,602 at September 30, 2018 and December 31, 2017, respectively)	81,835	76,173
Prepaid expenses and other current assets	17,567	15,700
Total current assets	936,899	913,089
Long-term marketable securities	0	25,032
Property, equipment and software, net	110,899	103,651
Goodwill	106,323	107,954
Intangibles, net	14,242	16,893
Restricted cash	22,121	18,554
Other non-current assets	42,773	40,428
Total assets	1,233,257	1,225,601
Current liabilities:
Accounts payable	6,829	9,033
Accrued liabilities	58,564	73,665
Deferred revenue	3,392	3,469
Total current liabilities	68,785	86,167
Long-term liabilities	34,978	30,737
Total liabilities	103,763	116,904
Commitments and contingencies (Note 12)
Stockholders' equity:
Common stock, $0.000001 par value, 200,000,000 shares authorized – 84,375,021 shares issued and outstanding at September 30, 2018 and 83,724,916 shares issued and outstanding at December 31, 2017	0	0
Additional paid-in capital	1,109,199	1,038,017
Treasury stock	0	(46)
Accumulated other comprehensive loss	(10,225)	(8,444)
Retained earnings	30,520	79,170
Total stockholders' equity	1,129,494	1,108,697
Total liabilities and stockholders' equity	$ 1,233,257	$ 1,225,601

[1] As of January 1, 2018, the Company adopted Accounting Standards Update 2014-09, "Revenue from Contracts with Customers (Topic 606)" ("ASC 606"), using the full retrospective method. Accordingly, the Company has recast certain amounts in the prior period presented. See Note 1 below for additional discussion.