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Goodwill and Related Intangible Assets (Schedule of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020
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Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Finite-lived intangible assets | $ 154,981 | $ 155,183
Total acquired intangible assets, Gross Carrying Amount | 211,651 | 211,753
Accumulated Amortization, Finite-lived intangible assets | 59,774 | 55,388
Total acquired intangible assets, Accumulated Amortization | 59,774 | 55,388
Trademarks |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Finite-lived intangible assets | 5,831 | 5,818
Accumulated Amortization, Finite-lived intangible assets | 3,574 | 3,385
Unpatented technology |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Finite-lived intangible assets | 38,892 | 38,752
Accumulated Amortization, Finite-lived intangible assets | 18,479 | 17,765
Customer relationships |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Finite-lived intangible assets | 98,135 | 98,500
Accumulated Amortization, Finite-lived intangible assets | 33,298 | 31,580
Non-compete agreements |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Finite-lived intangible assets | 4,888 | 4,885
Accumulated Amortization, Finite-lived intangible assets | 1,913 | 1,747
Backlog |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Finite-lived intangible assets | 7,235 | 7,228
Accumulated Amortization, Finite-lived intangible assets | 2,510 | 911
Trademarks |  |
Finite-Lived Intangible Assets [Line Items] |  |
Gross Carrying Amount, Indefinite-lived intangible assets | 56,670 | 56,570
Accumulated Amortization, Indefinite-lived intangible assets | $ 0 | $ 0

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