CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 881,501	$ 822,479
Short-term investments	286	381
Accounts receivable, less allowance for doubtful accounts of $6,800 and $5,700, respectively	124,659	107,192
Other receivables and current assets	263,820	239,349
Total current assets	1,270,266	1,169,401
Property and equipment, net	57,096	54,677
Goodwill	1,378,553	1,337,215
Other intangible assets, net	157,625	172,619
Other long-term assets	35,972	24,287
Deferred income taxes	42,111	42,327
Total assets	2,941,623	2,800,526
Current liabilities:
Accounts payable	6,042	7,395
Accrued bonuses and commissions	69,925	49,487
Accrued income taxes	5,760	5,263
Other accrued expenses and liabilities	86,335	73,676
Deferred revenue	440,491	403,279
Total current liabilities	608,553	539,100
Long-term liabilities:
Deferred income taxes	1,461	2,259
Other long-term liabilities	85,778	50,762
Total long-term liabilities	87,239	53,021
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $.01 par value; 2,000,000 shares authorized; zero shares issued or outstanding	0	0
Common stock, $.01 par value; 300,000,000 shares authorized; 93,236,023 shares issued	932	932
Additional paid-in capital	873,357	883,010
Retained earnings	2,316,916	2,057,665
Treasury stock, at cost: 9,044,498 and 7,548,188 shares, respectively	(907,530)	(675,550)
Accumulated other comprehensive loss	(37,844)	(57,652)
Total stockholders’ equity	2,245,831	2,208,405
Total liabilities and stockholders’ equity	$ 2,941,623	$ 2,800,526