CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 234,128	$ 603,623
Accounts receivable (less allowance for losses and sales adjustments of $10,575 in 2021 and $9,255 in 2020)	538,119	382,319
Short-term investments	49,355	72,187
Prepaid expenses	47,546	30,864
Income tax receivable	3,509	21,598
Other current assets	5,599	2,479
Total current assets	878,256	1,113,070
Accounts receivable, long-term	14,917	21,417
Operating lease right-of-use assets	40,449	18,734
Property and equipment, net	176,745	168,004
Other assets:
Software development costs, net	22,570	9,121
Goodwill	2,355,144	838,428
Other intangibles, net	1,086,457	322,068
Non-current investments	64,916	82,640
Other non-current assets	43,484	33,792
Total assets	4,682,938	2,607,274
Current liabilities:
Accounts payable	100,569	14,011
Accrued liabilities	180,281	83,084
Operating lease liabilities	10,125	5,904
Deferred revenue	495,250	461,278
Current portion of term loans	30,000	0
Total current liabilities	816,225	564,277
Revolving credit facility	0	0
Term loans	805,535	0
Convertible senior notes due 2026, net	592,335	0
Deferred revenue, long-term	53	100
Deferred income taxes	227,537	40,507
Operating lease liabilities, long-term	37,348	16,279
Other long-term liabilities	3,132	0
Total liabilities	2,482,165	621,163
Commitments and contingencies	0	0
Shareholders' equity:
Preferred stock, $10.00 par value; 1,000,000 shares authorized; none issued	0	0
Common stock, $0.01 par value; 100,000,000 shares authorized; 48,147,969 shares issued and outstanding as of September 30, 2021 and December 31, 2020	481	481
Additional paid-in capital	1,010,212	905,332
Accumulated other comprehensive loss, net of tax	(46)	(46)
Retained earnings	1,218,832	1,112,156
Treasury stock, at cost; 7,197,156 and 7,608,627 shares in 2021 and 2020, respectively	(28,706)	(31,812)
Total shareholders' equity	2,200,773	1,986,111
Total liabilities and shareholders' equity	$ 4,682,938	$ 2,607,274