Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 568,824	$ 545,761
Short-term investments, available-for-sale	355,957	43,055
Accounts receivable, net of allowances of $15,643 and $9,557 at September 30, 2020 and December 31, 2019, respectively	564,782	720,359
Inventories, net	15,887	15,898
Prepaid expenses and other current assets	233,514	187,659
Total current assets	1,738,964	1,512,732
Long-term investments, available-for-sale	13,591	16,640
Property and equipment, net	212,353	231,894
Operating lease right-of-use assets, net	187,530	206,154
Goodwill	1,798,408	1,798,408
Other intangible assets, net	87,124	108,478
Deferred tax assets, net	395,201	361,814
Other assets	175,423	152,806
Total assets	4,608,594	4,388,926
Current liabilities:
Accounts payable	101,339	84,538
Accrued expenses and other current liabilities	404,230	331,680
Income taxes payable	101,375	60,036
Current portion of deferred revenues	1,313,883	1,352,333
Total current liabilities	1,920,827	1,828,587
Long-term portion of deferred revenues	378,421	443,458
Long-term debt	1,732,069	742,926
Long-term income taxes payable	232,086	259,391
Operating lease liabilities	195,193	209,382
Other liabilities	81,198	67,526
Commitments and contingencies
Stockholders' equity:
Preferred stock at $.01 par value: 5,000 shares authorized, none issued and outstanding	0	0
Common stock at $.001 par value: 1,000,000 shares authorized; 321,557 and 318,760 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively	322	319
Additional paid-in capital	6,527,362	6,249,065
Retained earnings	4,916,940	4,660,145
Accumulated other comprehensive loss	(4,327)	(5,127)
Stockholders' equity before treasury stock	11,440,297	10,904,402
Less - common stock in treasury, at cost (198,568 and 188,693 shares at September 30, 2020 and December 31, 2019, respectively)	(11,371,497)	(10,066,746)
Total stockholders' equity	68,800	837,656
Total liabilities and stockholders' equity	$ 4,608,594	$ 4,388,926