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Retirement Plans - Schedule of Plan Assets Fair Value Hierarchy (Details) - USD ($) $ in Thousands | Dec. 31, 2023 | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 5,100 | $ 4,900 |
United Kingdom Subsidiary | UK Plan |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 223,077 | 210,284 | $ 356,532
United Kingdom Subsidiary | UK Plan | Total plan assets in fair value hierarchy |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 117,235 | 89,446 |
United Kingdom Subsidiary | UK Plan | Total plan assets in fair value hierarchy | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 8,797 | 19,829 |
United Kingdom Subsidiary | UK Plan | Total plan assets in fair value hierarchy | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 108,438 | 69,617 |
United Kingdom Subsidiary | UK Plan | Total plan assets in fair value hierarchy | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Corporate debt funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 44,504 | 23,998 |
United Kingdom Subsidiary | UK Plan | Corporate debt funds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Corporate debt funds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 44,504 | 23,998 |
United Kingdom Subsidiary | UK Plan | Corporate debt funds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Government bond funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 63,934 | 45,619 |
United Kingdom Subsidiary | UK Plan | Government bond funds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Government bond funds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 63,934 | 45,619 |
United Kingdom Subsidiary | UK Plan | Government bond funds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Cash and cash equivalents |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 8,797 | 19,829 |
United Kingdom Subsidiary | UK Plan | Cash and cash equivalents | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 8,797 | 19,829 |
United Kingdom Subsidiary | UK Plan | Cash and cash equivalents | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Cash and cash equivalents | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
United Kingdom Subsidiary | UK Plan | Debt funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | $ 85,786 | $ 99,990 |
Fair value of plan assets by hierarchy and NAV [Extensible Enumeration] |  | Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value Measured at Net Asset Value Per Share [Member] |
United Kingdom Subsidiary | UK Plan | Real estate funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | $ 20,056 | $ 20,848 |
Fair value of plan assets by hierarchy and NAV [Extensible Enumeration] |  | Fair Value Measured at Net Asset Value Per Share [Member] | Fair Value Measured at Net Asset Value Per Share [Member] |
[1] | Certain investments measured using net asset value (“NAV”) as a practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the total fair value of plan assets. NAV is determined by the respective fund manager based on the fair value of the underlying assets held by the fund, less its liabilities, divided by the number of units outstanding.

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