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Goodwill and Identifiable Assets (Tables) | 3 Months Ended
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Mar. 31, 2025
Goodwill and Intangible Assets Disclosure [Abstract] |
Schedule of Goodwill | Goodwill by reportable segment is as follows (in millions):
| Commercial |  | Federal Government |  |  |  | Total
Balance as of December 31, 2023 | $ | 1,075.8 |  |  | $ | 818.3 |  |  |  |  | $ | 1,894.1 |
Translation adjustment | (1.0) |  |  | — |  |  |  |  | (1.0) |
Balance as of December 31, 2024 | 1,074.8 |  |  | 818.3 |  |  |  |  | 1,893.1 |
Acquisition of TopBloc | 245.9 |  |  | — |  |  |  |  | 245.9 |
Translation adjustment | 0.5 |  |  | — |  |  |  |  | 0.5 |
Balance at March 31, 2025 | $ | 1,321.2 |  |  | $ | 818.3 |  |  |  |  | $ | 2,139.5 |
Schedule of Acquired Intangible Assets | Acquired identifiable intangible assets consisted of the following (in millions):
|  |  | March 31, 2025 |  | December 31, 2024 |  |
| Estimated Useful Life in Years |  | Gross Carrying Amount |  | Accumulated Amortization |  | Net Carrying Amount |  | Gross Carrying Amount |  | Accumulated Amortization |  | Net Carrying Amount |  |
Subject to amortization: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Customer and contractual relationships | 6 - 13 |  | $ | 447.4 |  |  | $ | 258.2 |  |  | $ | 189.2 |  |  | $ | 405.3 |  |  | $ | 245.0 |  |  | $ | 160.3 |  |  |
Non-compete agreements | 3 - 7 |  | 21.4 |  |  | 15.7 |  |  | 5.7 |  |  | 21.4 |  |  | 14.7 |  |  | 6.7 |  |  |
Internally-developed software | 3 |  | 4.4 |  |  | 0.1 |  |  | 4.3 |  |  | — |  |  | — |  |  | — |  |  |
|  |  | 473.2 |  |  | 274.0 |  |  | 199.2 |  |  | 426.7 |  |  | 259.7 |  |  | 167.0 |  |  |
Not subject to amortization: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Trademarks |  |  | 305.2 |  |  | — |  |  | 305.2 |  |  | 272.8 |  |  | — |  |  | 272.8 |  |  |
|  |  | $ | 778.4 |  |  | $ | 274.0 |  |  | $ | 504.4 |  |  | $ | 699.5 |  |  | $ | 259.7 |  |  | $ | 439.8 |  |  |
Schedule of Estimated Future Amortization Expense | Estimated future amortization expense is as follows (in millions):
Remainder of 2025 | $ | 50.2 |
2026 | 54.1 |
2027 | 41.2 |
2028 | 23.1 |
2029 | 17.0 |
Thereafter | 13.6 |
| $ | 199.2 |

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