Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
ASSETS
Cash and cash equivalents	$ 575,615	$ 209,474
Accounts receivable, net of allowances of $12,701 and $10,422, respectively	261,928	221,615
Prepaid expenses and other current assets	49,347	29,242
Total current assets	886,890	460,331
Long-term investments	100,079	83,828
Property and equipment, net	127,817	98,813
Operating lease right-of-use assets	125,822	0
Trade names, net	138,029	142,888
Customer relationships, net	238,502	191,208
Goodwill	1,633,033	1,380,376
Other purchased intangibles, net	180,022	192,372
Deferred Tax Assets, Net, Noncurrent	59,976	0
Other assets	15,676	11,014
TOTAL ASSETS	3,505,846	2,560,830
LIABILITIES AND STOCKHOLDERS' EQUITY
Accounts payable and accrued expenses	238,059	166,521
Income taxes payable, current	17,758	12,915
Deferred revenue, current	162,855	127,568
Operating Lease, Liability, Current	26,927	0
Long-term Debt, Current Maturities	385,532	0
Other current liabilities	1,973	318
Total current liabilities	833,104	307,322
Long-term debt	1,062,929	1,013,129
Deferred revenue, noncurrent	12,744	13,200
Operating lease liabilities, noncurrent	104,070	0
Income taxes payable, noncurrent	11,675	11,675
Liability for uncertain tax positions	52,451	59,644
Deferred income taxes, noncurrent	107,453	69,048
Other long-term liabilities	10,228	51,068
TOTAL LIABILITIES	2,194,654	1,525,086
Commitments and contingencies	0	0
Common stock, $0.01 par value. Authorized 95,000,000 at December 31, 2019 and 2018; total issued 47,654,929 and 48,082,800 shares at December 31, 2019 and 2018, respectively; total outstanding 47,654,929 and 47,482,800 shares at December 31, 2019 and 2018, respectively.	476	481
Additional paid-in capital	465,652	354,210
Treasury stock, at cost (zero and 600,000 shares at December 31, 2019 and 2018, respectively).	0	(42,543)
Retained earnings	891,526	769,575
Accumulated other comprehensive loss	(46,462)	(45,979)
TOTAL STOCKHOLDERS’ EQUITY	1,311,192	1,035,744
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	3,505,846	2,560,830
Series A Preferred Stock [Member]
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value	0	0
Series B Preferred Stock [Member]
LIABILITIES AND STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value	$ 0	$ 0