CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 112,082	$ 420,244
Restricted cash	901	938
Short-term investments	587,093	254,927
Accounts receivable, net	110,761	165,364
Prepaid expenses and other current assets	27,629	19,180
Total current assets	838,466	860,653
Property and equipment, net	51,861	53,359
Capitalized software development costs, net	0	2,499
Deposits and other assets	7,549	7,411
Deferred tax assets, net	15,628	9,297
Total assets	913,504	933,219
Current liabilities:
Accounts payable and accrued expenses	23,002	30,711
Accrued compensation and employee benefits	37,819	41,498
Deferred revenue and advance payments	151,043	198,734
Total current liabilities	211,864	270,943
Deferred revenue and advance payments	4,923	6,400
Other long-term liabilities	61,290	50,146
Deferred tax liabilities	4	4
Total liabilities	278,081	327,493
Commitments and Contingencies
Stockholders' Equity
Preferred stock undesignated, $0.001 par value; 5,000 shares authorized; no shares issued or outstanding	0	0
Additional paid-in capital	573,474	559,918
Treasury stock, at cost; 6,405 shares	(475,184)	(475,184)
Accumulated other comprehensive loss	(8,718)	(5,659)
Retained earnings	545,833	526,633
Total stockholders' equity	635,423	605,726
Total liabilities and stockholders' equity	913,504	933,219
Class A
Stockholders' Equity
Common stock	16	16
Class B Convertible
Stockholders' Equity
Common stock	$ 2	$ 2