CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 729,180	$ 881,501
Short-term investments	211	286
Accounts receivable, less allowance for doubtful accounts of $8,100 and $6,800, respectively	235,547	124,659
Other receivables and current assets	162,629	263,820
Total current assets	1,127,567	1,270,266
Property and equipment, net	57,902	57,096
Goodwill	1,575,567	1,378,553
Other intangible assets, net	219,564	157,625
Other long-term assets	53,226	35,972
Deferred income taxes	22,285	42,111
Total assets	3,056,111	2,941,623
Current liabilities:
Accounts payable	6,767	6,042
Accrued bonuses and commissions	46,720	69,925
Accrued income taxes	5,911	5,760
Other accrued expenses and liabilities	83,169	86,335
Deferred revenue - current	272,872	440,491
Total current liabilities	415,439	608,553
Long-term liabilities:
Deferred income taxes	29,955	1,461
Other long-term liabilities	62,171	85,778
Total long-term liabilities	92,126	87,239
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	850,616	873,357
Retained earnings	2,766,259	2,316,916
Treasury stock, at cost: 9,213,790 and 9,044,498 shares, respectively	(1,008,370)	(907,530)
Accumulated other comprehensive loss	(60,891)	(37,844)
Total stockholders' equity	2,548,546	2,245,831
Total liabilities and stockholders' equity	$ 3,056,111	$ 2,941,623