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Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands | 3 Months Ended | 4 Months Ended | 5 Months Ended | 9 Months Ended |
--- | --- | --- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | May 17, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | $ 5,300 |  | $ 5,300 |  |  |
Contingent consideration, gain (loss) due to change in value | (1,200) | $ (200) | (100) |  | $ (3,100) |
Contingent consideration, settlements |  |  | 600 | $ 200 | $ 300 |
Level 3 |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | 5,300 |  | 5,300 |  |  | $ 6,200
Prepaid Expenses and Other Current Assets |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | 800 |  | 800 |  |  |
Other Noncurrent Assets |  |  |  |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |  |  |  |
Contingent consideration arrangement | $ 4,500 |  | $ 4,500 |  |  |

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