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Retirement Plans - Schedule of Plan Assets Fair Value Hierarchy (Details) - United Kingdom Subsidiary - UK Plan - USD ($) $ in Thousands | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | --- | ---
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | $ 356,532 | $ 347,411 | $ 307,001
Total plan assets in fair value hierarchy |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 217,897 | 225,997 |
Total plan assets in fair value hierarchy | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 58,772 | 59,246 |
Total plan assets in fair value hierarchy | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 159,125 | 166,751 |
Total plan assets in fair value hierarchy | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Corporate debt funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 67,226 | 65,486 |
Corporate debt funds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Corporate debt funds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 67,226 | 65,486 |
Corporate debt funds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Government bond funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 91,899 | 57,133 |
Government bond funds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Government bond funds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 91,899 | 57,133 |
Government bond funds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Equity funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 44,132 |
Equity funds | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 0 |
Equity funds | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 44,132 |
Equity funds | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  |  | 0 |
Cash and cash equivalents |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 58,772 | 59,246 |
Cash and cash equivalents | Level 1 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 58,772 | 59,246 |
Cash and cash equivalents | Level 2 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Cash and cash equivalents | Level 3 |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets |  | 0 | 0 |
Debt funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | $ 111,971 | $ 96,196 |
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] |
Real estate funds |  |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |  |
Fair value of plan assets | [1] | $ 26,664 | $ 25,218 |
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.

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