Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 524,881	$ 545,761
Short-term investments, available-for-sale	25,644	43,055
Accounts receivable, net of allowances of $18,374 and $9,557 at March 31, 2020 and December 31, 2019, respectively	700,026	720,359
Inventories, net	17,323	15,898
Prepaid expenses and other current assets	193,179	187,659
Total current assets	1,461,053	1,512,732
Long-term investments, available-for-sale	12,721	16,640
Property and equipment, net	225,098	231,894
Operating lease right-of-use assets	204,974	206,154
Goodwill	1,798,408	1,798,408
Other intangible assets, net	101,132	108,478
Deferred tax assets, net	367,074	361,814
Other assets	160,767	152,806
Total assets	4,331,227	4,388,926
Current liabilities:
Accounts payable	105,218	84,538
Accrued expenses and other current liabilities	362,386	331,680
Income taxes payable	65,989	60,036
Current portion of deferred revenues	1,340,456	1,352,333
Total current liabilities	1,874,049	1,828,587
Long-term portion of deferred revenues	414,347	443,458
Long-term debt	1,730,961	742,926
Long-term income taxes payable	259,391	259,391
Operating lease liabilities	201,336	209,382
Other liabilities	70,072	67,526
Commitments and contingencies
Stockholders' (deficit) 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; 320,437 and 318,760 shares issued and outstanding at March 31, 2020 and December 31, 2019, respectively	320	319
Additional paid-in capital	6,125,589	6,249,065
Retained earnings	4,794,964	4,660,145
Accumulated other comprehensive loss	(7,810)	(5,127)
Stockholders' equity before treasury stock	10,913,063	10,904,402
Less - common stock in treasury, at cost (197,436 and 188,693 shares at March 31, 2020 and December 31, 2019, respectively)	(11,131,992)	(10,066,746)
Total stockholders' (deficit) equity	(218,929)	837,656
Total liabilities and stockholders' (deficit) equity	$ 4,331,227	$ 4,388,926