Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net income	$ 793,560,000	$ 266,745,000	$ 233,290,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	212,405,000	218,984,000	211,779,000
Stock-based compensation expense	98,570,000	62,540,000	69,008,000
Deferred taxes	(41,567,000)	(53,190,000)	(55,787,000)
Loss from divested operations	0	0	2,075,000
Loss on impairment of lease related assets, net	49,537,000	0	0
Loss on extinguishment of debt	0	44,814,000	0
Gain on sale of an equity security	0	0	(9,120,000)
Reduction in the carrying amount of operating lease right-of-use assets	75,125,000	81,851,000	86,466,000
Amortization and write-off of deferred financing fees	4,162,000	8,424,000	6,497,000
Amortization of deferred swap losses from de-designation	0	10,320,000	0
Gain on de-designated swaps	(20,204,000)	(2,157,000)	0
Changes in assets and liabilities, net of acquisitions and divestitures:
Fees receivable, net	(145,346,000)	99,409,000	(66,729,000)
Deferred commissions	(124,874,000)	8,656,000	(30,315,000)
Prepaid expenses and other current assets	(15,913,000)	37,895,000	18,985,000
Other assets	(18,287,000)	(8,950,000)	(27,303,000)
Deferred revenues	324,059,000	15,998,000	181,203,000
Accounts payable and accrued and other liabilities	121,243,000	111,939,000	(54,613,000)
Cash provided by operating activities	1,312,470,000	903,278,000	565,436,000
Investing activities:
Additions to property, equipment and leasehold improvements	(59,834,000)	(83,888,000)	(149,016,000)
Acquisitions - cash paid (net of cash acquired)	(22,939,000)	0	(25,989,000)
Other	2,306,000	0	0
Proceeds from the sale of an equity security	0	0	14,120,000
Cash used in investing activities	(80,467,000)	(83,888,000)	(160,885,000)
Financing activities:
Proceeds from employee stock purchase plan	18,173,000	18,085,000	17,629,000
Proceeds from borrowings	600,000,000	2,000,000,000	5,000,000
Early redemption premium payment	0	(30,752,000)	0
Payments for deferred financing fees	(7,320,000)	(25,786,000)	0
Proceeds from revolving credit facility	0	332,000,000	309,000,000
Payments on revolving credit facility	(5,000,000)	(475,000,000)	(316,000,000)
Payments on borrowings	(107,915,000)	(2,058,469,000)	(102,579,000)
Purchases of treasury stock	(1,655,547,000)	(176,302,000)	(199,042,000)
Cash used in financing activities	(1,157,609,000)	(416,224,000)	(285,992,000)
Net increase in cash and cash equivalents and restricted cash	74,394,000	403,166,000	118,559,000
Effects of exchange rates on cash and cash equivalents and restricted cash	(26,375,000)	28,581,000	3,614,000
Cash and cash equivalents and restricted cash, beginning of year	712,583,000	280,836,000	158,663,000
Cash and cash equivalents and restricted cash, end of year	760,602,000	712,583,000	280,836,000
Cash paid during the year for:
Interest	101,885,000	112,249,000	102,298,000
Income taxes, net of refunds received	$ 253,379,000	$ 33,921,000	$ 119,156,000