Unaudited Consolidated Statements of Comprehensive Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Revenues
Total revenues	$ 530.5	$ 499.9
Cost of revenues
Operating expenses	66.3	63.7
Depreciation and amortization	18.3	15.0
Total cost of revenues	84.6	78.7
Administrative expenses
Sales and marketing	110.9	115.5
Research and development	62.3	50.5
General and administrative	66.0	(48.1)
Depreciation and amortization	21.6	17.5
Total administrative expenses	260.8	135.4
Total operating expenses	345.4	214.1
Operating income	185.1	285.8
Interest expense	(0.8)	(0.8)
Other income (expense), net	6.0	5.0
Income before income taxes	190.3	290.0
Provision for income taxes	50.9	42.8
Net income	$ 139.4	$ 247.2
Earnings per share, basic	$ 2.49	$ 4.37
Earnings per share, diluted	$ 2.48	$ 4.37
Weighted average shares outstanding:
Basic	55,973	56,546
Diluted	56,279	56,552
Comprehensive earnings:
Net income	$ 139.4	$ 247.2
Unrealized net gains on available-for-sale securities	0.6	0.8
Tax effect	(0.1)	(0.3)
Other comprehensive income, net of tax	0.5	0.5
Comprehensive earnings:	139.9	247.7
Recurring and Other [Member]
Revenues
Total revenues	500.0	466.0
Interest on Funds Held for Clients [Member]
Revenues
Total revenues	$ 30.5	$ 33.9