Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 513,993	$ 752,895
Short-term investments, available-for-sale	13,186	124,113
Accounts receivable, net of allowances of $33,279 and $25,868 at December 31, 2021 and 2020, respectively	885,311	858,009
Inventories, net	23,158	20,089
Prepaid expenses and other current assets	283,337	236,000
Total current assets	1,718,985	1,991,106
Long-term investments, available-for-sale	14,754	14,365
Property and equipment, net	219,031	208,811
Operating lease right-of-use assets, net	154,685	187,129
Goodwill	3,400,792	1,798,408
Other intangible assets, net	760,293	81,491
Deferred tax assets, net	417,016	386,504
Other assets	289,961	222,533
Total assets	6,975,517	4,890,347
Current liabilities:
Accounts payable	165,250	92,266
Accrued expenses and other current liabilities	444,767	507,185
Income taxes payable	35,996	42,760
Current portion of deferred revenues	1,708,058	1,510,216
Total current liabilities	2,354,071	2,152,427
Long-term portion of deferred revenues	329,535	392,360
Long-term debt	3,326,327	1,732,622
Long-term income taxes payable	204,782	232,086
Operating lease liabilities	166,014	195,767
Other liabilities	47,531	72,942
Commitments and contingencies
Stockholders' equity:
Preferred stock at $0.01 par value: 5,000 shares authorized, none issued and outstanding	0	0
Common stock at $0.001 par value: 1,000,000 shares authorized; 325,174 and 321,964 shares issued and outstanding at December 31, 2021 and 2020, respectively	325	322
Additional paid-in capital	7,041,576	6,608,018
Retained earnings	5,100,624	4,984,333
Accumulated other comprehensive loss	(2,896)	(3,649)
Stockholders' equity before treasury stock	12,139,629	11,589,024
Less - common stock in treasury, at cost (200,313 and 199,443 shares at December 31, 2021 and 2020, respectively)	(11,592,372)	(11,476,881)
Total stockholders' equity	547,257	112,143
Total liabilities and stockholders' equity	$ 6,975,517	$ 4,890,347