Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Operating activities:
Net income	$ 729,231	$ 1,253,715	$ 882,466
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	200,309	202,315	191,103
Stock-based compensation expense	155,877	154,784	129,841
Deferred taxes	828	(162,081)	(64,173)
Goodwill impairment	150,000	0	0
Gain from sale of divested operation	0	0	(135,410)
Loss on impairment of lease related assets, net	4,766	10,909	20,368
Reduction in the carrying amount of operating lease right-of-use assets	64,196	65,742	70,207
Amortization and write-off of deferred financing fees and unamortized discounts	4,288	4,591	4,689
Gain on de-designated swaps	(489)	(3,870)	(3,925)
Changes in assets and liabilities, net of acquisitions and divestitures:
Fees receivable, net	38,027	(137,768)	(24,662)
Deferred commissions	25,250	(41,555)	(13,716)
Prepaid expenses and other current assets	1,760	(28,933)	(7,893)
Other assets	(30,939)	(43,503)	(34,528)
Deferred revenues	(41,944)	181,180	169,917
Accounts payable and accrued and other liabilities	(10,795)	29,396	(28,547)
Cash provided by operating activities	1,290,365	1,484,922	1,155,737
Investing activities:
Additions to property, equipment and leasehold improvements	(115,142)	(101,737)	(103,124)
Acquisitions - cash paid (net of cash acquired)	0	(2,000)	(3,800)
Proceeds from sale of divested operation	0	0	161,081
Cash (used in) provided by investing activities	(115,142)	(103,737)	54,157
Financing activities:
Proceeds from employee stock purchase plan	32,450	28,187	25,107
Proceeds from issuance of long-term debt, net of discounts	799,859	0	0
Payments for deferred financing fees	(6,480)	(2,972)	0
Proceeds from revolving credit facility	0	274,400	0
Payments on revolving credit facility	(274,400)	0	0
Payments on long-term debt	0	(274,400)	(7,800)
Purchases of treasury stock	(1,991,147)	(735,358)	(606,188)
Cash used in financing activities	(1,439,718)	(710,143)	(588,881)
Net (decrease) increase in cash and cash equivalents and restricted cash	(264,495)	671,042	621,013
Effects of exchange rates on cash and cash equivalents and restricted cash	53,869	(57,494)	(13)
Cash and cash equivalents and restricted cash, beginning of year	1,933,147	1,319,599	698,599
Cash and cash equivalents and restricted cash, end of year	1,722,521	1,933,147	1,319,599
Cash paid during the year for:
Interest	99,503	100,085	119,038
Income taxes, net of refunds received	$ 209,557	$ 312,895	$ 306,682