CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 912,672	$ 872,094
Short-term investments	479	288
Accounts receivable, less allowance for doubtful accounts of $14,000 and $8,700, respectively	537,564	433,479
Other receivables and current assets	268,522	249,619
Total current assets	1,719,237	1,555,480
Long-term assets:
Property and equipment, net	96,503	83,636
Operating lease right-of-use assets	137,730	105,671
Goodwill	3,038,306	2,413,280
Other intangible assets, net	694,865	476,711
Other long-term assets	225,119	180,032
Deferred income taxes	28,830	24,077
Total long-term assets	4,221,353	3,283,407
Total assets	5,940,590	4,838,887
Current liabilities:
Accounts payable	18,691	14,298
Accrued bonuses and commissions	112,491	101,546
Accrued income taxes	26,116	9,996
Current portion of long-term debt	0	75,000
Other accrued expenses and liabilities	199,466	142,947
Deferred revenue	372,061	351,353
Total current liabilities	728,825	695,140
Long-term liabilities:
Deferred income taxes	110,321	78,643
Long-term operating lease liabilities	120,940	91,768
Long-term debt	798,118	423,531
Other long-term liabilities	84,514	96,426
Total long-term liabilities	1,113,893	690,368
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value; 2,000,000 shares authorized; zero shares issued or outstanding	0	0
Common stock, $0.01 par value; 300,000,000 shares authorized; 95,266,320 and 94,627,585 shares issued, respectively	953	946
Additional paid-in capital	1,434,203	1,188,939
Retained earnings	3,804,593	3,370,706
Treasury stock, at cost: 8,693,809 and 8,893,177 shares, respectively	(1,124,102)	(1,041,831)
Accumulated other comprehensive loss	(17,775)	(65,381)
Total stockholders’ equity	4,097,872	3,453,379
Total liabilities and stockholders’ equity	$ 5,940,590	$ 4,838,887