CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 885,493	$ 881,501
Short-term investments	4,275	286
Accounts receivable, less allowance for doubtful accounts of $6,800	256,560	124,659
Other receivables and current assets	181,001	263,820
Total current assets	1,327,329	1,270,266
Property and equipment, net	55,806	57,096
Goodwill	1,379,458	1,378,553
Other intangible assets, net	146,396	157,625
Other long-term assets	34,731	35,972
Deferred income taxes	15,446	42,111
Total assets	2,959,166	2,941,623
Current liabilities:
Accounts payable	7,259	6,042
Accrued bonuses and commissions	23,192	69,925
Accrued income taxes	4,870	5,760
Other accrued expenses and liabilities	95,053	86,335
Deferred revenue	311,718	440,491
Total current liabilities	442,092	608,553
Long-term liabilities:
Deferred income taxes	28,849	1,461
Other long-term liabilities	80,865	85,778
Total long-term liabilities	109,714	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	833,414	873,357
Retained earnings	2,584,328	2,316,916
Treasury stock, at cost: 9,301,725 and 9,044,498 shares, respectively	(981,713)	(907,530)
Accumulated other comprehensive loss	(29,601)	(37,844)
Total stockholders' equity	2,407,360	2,245,831
Total liabilities and stockholders' equity	$ 2,959,166	$ 2,941,623