Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 589,847	$ 615,615
Short-term investments	252,622	442,473
Receivables, net	1,161,361	1,168,712
Inventory	28,159	23,027
Prepaid expenses and other	417,465	401,160
Total current assets	2,449,454	2,650,987
Property and equipment, net	1,656,171	1,804,083
Right-of-use assets	82,940	104,536
Software development costs, net	1,000,357	1,009,349
Goodwill	1,131,121	914,520
Intangible assets, net	458,482	329,249
Long-term investments	461,984	510,220
Other assets	193,649	198,152
Total assets	7,434,158	7,521,096
Current liabilities:
Accounts payable	329,582	235,755
Long-term Debt, Current Maturities	225,000	0
Deferred revenue	531,234	393,293
Accrued payroll and tax withholdings	317,092	309,814
Other current liabilities	223,350	229,764
Total current liabilities	1,626,258	1,168,626
Long-term debt	1,611,256	1,336,069
Deferred Income Taxes, Noncurrent	395,177	376,035
Other liabilities	121,005	157,799
Total liabilities	3,753,696	3,038,529
Shareholders' Equity:
Common stock, $0.01 par value, 500,000,000 shares authorized, 380,232,975 shares issued at December 31, 2021 and 373,224,832 shares issued at December 31, 2020	3,802	3,732
Additional paid-in capital	2,717,244	2,288,806
Retained earnings	6,751,692	6,475,551
Treasury stock, 87,383,166 shares at December 31, 2021 and 67,371,686 shares at December 31, 2020	(5,664,718)	(4,164,718)
Accumulated other comprehensive loss, net	(127,558)	(120,804)
Total shareholders' equity	3,680,462	4,482,567
Total liabilities and shareholders' equity	$ 7,434,158	$ 7,521,096
Common Stock, par value	$ 0.01
Common Stock, Shares Authorized	500,000,000
Common stock, shares issued	380,232,975	373,224,832
Treasury stock, shares	87,383,166	67,371,686