CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ASSETS
Cash and cash equivalents	$ 242,652	$ 575,615
Short-term investments	663	0
Accounts receivable, net of allowances of $16,018 and $12,701, respectively	325,619	261,928
Prepaid expenses and other current assets	53,909	49,347
Total current assets	622,843	886,890
Long-term investments	97,495	100,079
Property and equipment, net	156,577	127,817
Operating lease right-of-use assets	105,845	125,822
Trade names, net	187,902	138,029
Customer relationships, net	377,194	238,502
Goodwill	1,867,430	1,633,033
Other purchased intangibles, net	176,473	180,022
Deferred income taxes, noncurrent	56,545	59,976
Other assets	17,027	15,676
TOTAL ASSETS	3,665,331	3,505,846
LIABILITIES AND STOCKHOLDERS’ EQUITY
Accounts payable and accrued expenses	230,651	238,059
Income taxes payable, current	31,753	17,758
Deferred revenue, current	190,644	162,855
Operating lease liabilities, current	32,211	26,927
Current portion of long-term debt	396,801	385,532
Other current liabilities	497	1,973
Total current liabilities	882,557	833,104
Total long-term debt, less current portion	1,182,220	1,062,929
Deferred revenue, noncurrent	14,440	12,744
Operating lease liabilities, noncurrent	99,177	104,070
Income taxes payable, noncurrent	11,675	11,675
Liability for uncertain tax positions	57,081	52,451
Deferred income taxes, noncurrent	162,700	107,453
Other long-term liabilities	44,463	10,228
TOTAL LIABILITIES	2,454,313	2,194,654
Commitments and contingencies	0	0
Common stock, $0.01 par value. Authorized 95,000,000 at December 31, 2020 and 2019; total issued and outstanding 44,346,630 and 47,654,929 shares at December 31, 2020 and 2019, respectively.	443	476
Additional paid-in capital	456,274	465,652
Retained earnings	809,107	891,526
Accumulated other comprehensive loss	(54,806)	(46,462)
TOTAL STOCKHOLDERS’ EQUITY	1,211,018	1,311,192
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	3,665,331	3,505,846
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