Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
ASSETS
Cash and cash equivalents	$ 546,467	$ 242,652
Short-term investments	0	663
Accounts receivable, net of allowances of $14,417 and $16,018, respectively	268,349	325,619
Prepaid expenses and other current assets	73,457	53,909
Total current assets	888,273	622,843
Long-term investments	110,718	97,495
Property and equipment, net	183,179	156,577
Operating lease right-of-use assets	88,331	105,845
Goodwill	1,861,332	1,867,430
Other purchased intangibles, net	160,943	176,473
Deferred income taxes, noncurrent	37,761	56,545
Other assets	19,901	17,027
TOTAL ASSETS	3,830,657	3,665,331
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable and accrued expenses	228,977	230,651
Income taxes payable, current	1,793	31,753
Deferred revenue, current	197,901	190,644
Operating lease liabilities, current	31,636	32,211
Current portion of long-term debt	568,054	396,801
Other current liabilities	36	497
Total current liabilities	1,028,397	882,557
Long-term debt	1,110,699	1,182,220
Deferred revenue, noncurrent	15,189	14,440
Operating lease liabilities, noncurrent	84,519	99,177
Income taxes payable, noncurrent	11,675	11,675
Liability for uncertain tax positions	54,178	57,081
Deferred income taxes, noncurrent	112,482	162,700
Other long-term liabilities	44,259	44,463
TOTAL LIABILITIES	2,461,398	2,454,313
Commitments and contingencies	0	0
Preferred stock, $0.01 par value	0	0
Common stock, $0.01 par value. Authorized 95,000,000; total issued and outstanding 47,825,827 and 44,346,630 shares at September 30, 2021 and December 31, 2020, respectively.	478	443
Additional paid-in capital	508,493	456,274
Retained earnings	931,477	809,107
Accumulated other comprehensive loss	(71,189)	(54,806)
TOTAL STOCKHOLDERS’ EQUITY	1,369,259	1,211,018
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	3,830,657	3,665,331
Trade names
ASSETS
Intangible assets, net (excluding goodwill)	178,322	187,902
Customer relationship
ASSETS
Intangible assets, net (excluding goodwill)	301,897	377,194
Series A Preferred Stock
LIABILITIES AND STOCKHOLDERS’ EQUITY
Preferred stock, $0.01 par value	0	0
Series B Preferred Stock
LIABILITIES AND STOCKHOLDERS’ EQUITY
Preferred stock, $0.01 par value	$ 0	$ 0