Revenue - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disaggregation of Revenue [Line Items]
Revenue	$ 2,762.6	$ 2,483.9	$ 5,298.4	$ 4,768.5
Americas
Disaggregation of Revenue [Line Items]
Revenue	1,997.8	1,804.1	3,826.8	3,492.5
EMEA
Disaggregation of Revenue [Line Items]
Revenue	295.1	259.8	565.2	464.7
APAC
Disaggregation of Revenue [Line Items]
Revenue	469.7	420.0	906.4	811.3
Services \| Over time
Disaggregation of Revenue [Line Items]
Revenue	1,801.3	1,668.0	3,544.1	3,271.7
Services \| Americas \| Over time
Disaggregation of Revenue [Line Items]
Revenue	1,267.6	1,202.1	2,501.2	2,388.9
Services \| EMEA \| Over time
Disaggregation of Revenue [Line Items]
Revenue	159.5	129.5	312.7	234.4
Services \| APAC \| Over time
Disaggregation of Revenue [Line Items]
Revenue	374.2	336.4	730.2	648.4
Leasing \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	628.5	493.1	1,126.1	911.5
Leasing \| Americas \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	523.5	388.0	937.4	734.3
Leasing \| EMEA \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	59.3	61.7	106.6	101.1
Leasing \| APAC \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	45.7	43.4	82.1	76.1
Capital markets \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	206.4	207.8	388.0	365.6
Capital markets \| Americas \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	160.9	171.7	302.8	287.6
Capital markets \| EMEA \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	26.7	23.7	46.5	41.7
Capital markets \| APAC \| At a point in time
Disaggregation of Revenue [Line Items]
Revenue	18.8	12.4	38.7	36.3
Valuation and other \| At a point in time or over time
Disaggregation of Revenue [Line Items]
Revenue	126.4	115.0	240.2	219.7
Valuation and other \| Americas \| At a point in time or over time
Disaggregation of Revenue [Line Items]
Revenue	45.8	42.3	85.4	81.7
Valuation and other \| EMEA \| At a point in time or over time
Disaggregation of Revenue [Line Items]
Revenue	49.6	44.9	99.4	87.5
Valuation and other \| APAC \| At a point in time or over time
Disaggregation of Revenue [Line Items]
Revenue	$ 31.0	$ 27.8	$ 55.4	$ 50.5