Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Segment Reporting Information [Line Items]
Net revenues	$ 2,017.5	$ 1,764.6	$ 5,843.9	$ 5,162.1
Cost of sales	614.5	542.9	1,801.8	1,566.1
SG&A expenses	830.0	725.1	2,395.0	2,123.9
Capital expenditures			37.6	39.2
Application Software
Segment Reporting Information [Line Items]
Net revenues	1,161.0	984.4	3,324.1	2,811.4
Network Software
Segment Reporting Information [Line Items]
Net revenues	413.4	367.1	1,174.7	1,102.1
Technology Enabled Products
Segment Reporting Information [Line Items]
Net revenues	443.1	413.1	1,345.1	1,248.6
Operating Segments
Segment Reporting Information [Line Items]
Net revenues	2,017.5	1,764.6	5,843.9	5,162.1
Cost of sales	614.5	542.9	1,801.8	1,566.1
SG&A expenses	751.7	654.8	2,165.7	1,929.4
Operating profit	651.3	566.9	1,876.4	1,666.6
Depreciation and other amortization	230.2	205.7	665.4	600.8
Capital expenditures	9.4	8.1	33.9	23.2
Capitalized software expenditures	16.0	12.9	42.8	33.4
Total assets:	33,791.2		33,791.2		$ 30,447.0
Operating Segments | Application Software
Segment Reporting Information [Line Items]
Net revenues	1,161.0	984.4	3,324.1	2,811.4
Cost of sales	360.0	311.6	1,049.0	871.8
SG&A expenses	478.0	413.0	1,380.7	1,189.1
Operating profit	323.0	259.8	894.4	750.5
Depreciation and other amortization	180.5	160.3	521.8	463.2
Capital expenditures	4.6	3.9	18.5	11.9
Capitalized software expenditures	16.0	12.4	42.8	32.4
Total assets:	25,495.2		25,495.2		23,600.9
Operating Segments | Network Software
Segment Reporting Information [Line Items]
Net revenues	413.4	367.1	1,174.7	1,102.1
Cost of sales	66.5	55.3	191.4	166.2
SG&A expenses	168.8	145.8	469.2	443.8
Operating profit	178.1	166.0	514.1	492.1
Depreciation and other amortization	43.8	40.3	126.4	120.9
Capital expenditures	2.5	1.7	7.1	4.0
Capitalized software expenditures	0.0	0.5	0.0	1.0
Total assets:	6,518.2		6,518.2		5,348.0
Operating Segments | Technology Enabled Products
Segment Reporting Information [Line Items]
Net revenues	443.1	413.1	1,345.1	1,248.6
Cost of sales	188.0	176.0	561.4	528.1
SG&A expenses	104.9	96.0	315.8	296.5
Operating profit	150.2	141.1	467.9	424.0
Depreciation and other amortization	5.9	5.1	17.2	16.7
Capital expenditures	2.3	2.5	8.3	7.3
Capitalized software expenditures	0.0	0.0	0.0	0.0
Total assets:	1,777.8		1,777.8		$ 1,498.1
Corporate
Segment Reporting Information [Line Items]
Unallocated corporate general and administrative expenses	$ 78.3	$ 70.3	$ 229.3	$ 194.5