Property and Equipment, Net - Summary of Property Plant and Equipment (Detail) - USD ($) $ in Millions |
Dec. 31, 2023 |
Dec. 31, 2022 |
|---|---|---|
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | $ 292.9 | $ 299.6 |
| Less: accumulated depreciation | (141.3) | (107.1) |
| Property and equipment, net | 151.7 | 192.5 |
| Leasehold improvements | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 186.7 | 192.3 |
| Office furniture and equipment | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 36.9 | 37.1 |
| Computer software and internally-developed software | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | 42.7 | 37.9 |
| Computer equipment | ||
| Property, Plant and Equipment [Line Items] | ||
| Property and equipment, gross | $ 26.7 | $ 32.3 |