Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Current assets:
Cash and cash equivalents	$ 493,834	$ 618,766	$ 1,205,182
Short-term investments, available-for-sale	55,372	583,615
Accounts receivable, net of allowances of $6,962 and $4,530 at September 30, 2019 and December 31, 2018, respectively	426,842	688,420
Inventories, net	18,518	21,905
Prepaid expenses and other current assets	199,434	174,195
Total current assets	1,194,000	2,086,901
Long-term investments, available-for-sale	21,374	574,319
Property and equipment, net	236,788	243,396
Operating lease right-of-use assets	218,625	0
Goodwill	1,798,408	1,802,670
Other intangible assets, net	119,055	167,187
Deferred tax assets, net	301,062	136,998
Other assets	141,781	124,578
Total assets	4,031,093	5,136,049
Current liabilities:
Accounts payable	72,659	75,551
Accrued expenses and other current liabilities	294,915	290,492
Income taxes payable	45,615	44,409
Current portion of convertible notes	0	1,155,445
Current portion of deferred revenues	1,200,496	1,345,243
Total current liabilities	1,613,685	2,911,140
Long-term portion of deferred revenues	415,076	489,329
Long-term debt	742,704	741,825
Long-term income taxes payable	259,391	285,627
Operating lease liabilities	221,032	0
Other liabilities	66,294	148,499
Commitments and contingencies
Temporary equity from convertible notes	0	8,110
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; 317,549 and 309,761 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	318	310
Additional paid-in capital	6,170,577	5,404,500
Retained earnings	4,500,876	4,169,019
Accumulated other comprehensive loss	(6,482)	(8,154)
Stockholders' equity before treasury stock	10,665,289	9,565,675
Less - common stock in treasury, at cost (187,661 and 178,327 shares at September 30, 2019 and December 31, 2018, respectively)	(9,952,378)	(9,014,156)
Total stockholders' equity	712,911	551,519
Total liabilities, temporary equity and stockholders' equity	$ 4,031,093	$ 5,136,049