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Pension Plans and Other Postretirement Benefits (Fair Value Of The Pension And Postretirement Benefit Plans Assets By Asset Category) (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | --- | ---
Pension Benefits | United States |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | $ 553,171 | $ 483,823 | $ 384,552
Pension Benefits | United States | Fair Value | Equity securities U.S. Companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 397,981 | 338,564 |
Pension Benefits | United States | Fair Value | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 21,313 | 20,751 |
Pension Benefits | United States | Fair Value | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 70 | 0 |
Pension Benefits | United States | Fair Value | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 1,680 |
Pension Benefits | United States | Fair Value | Money market instruments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 6,771 | 17,618 |
Pension Benefits | United States | Fair Value | Pooled investment funds Fixed Income Securities - Mutual Funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 18,420 | 9,576 |
Pension Benefits | United States | Fair Value | Pooled Investment Funds International Equities Mutual Funds [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 19,341 | 17,378 |
Pension Benefits | United States | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 463,896 | 403,887 |
Pension Benefits | United States | Level 1 | Equity securities U.S. Companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 397,981 | 338,564 |
Pension Benefits | United States | Level 1 | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 21,313 | 20,751 |
Pension Benefits | United States | Level 1 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 70 | 0 |
Pension Benefits | United States | Level 1 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 1 | Money market instruments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 6,771 | 17,618 |
Pension Benefits | United States | Level 1 | Pooled investment funds Fixed Income Securities - Mutual Funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 18,420 | 9,576 |
Pension Benefits | United States | Level 1 | Pooled Investment Funds International Equities Mutual Funds [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 19,341 | 17,378 |
Pension Benefits | United States | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 1,680 |
Pension Benefits | United States | Level 2 | Equity securities U.S. Companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 2 | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 2 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 2 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 1,680 |
Pension Benefits | United States | Level 2 | Money market instruments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 2 | Pooled investment funds Fixed Income Securities - Mutual Funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 2 | Pooled Investment Funds International Equities Mutual Funds [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Equity securities U.S. Companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Money market instruments |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Pooled investment funds Fixed Income Securities - Mutual Funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Level 3 | Pooled Investment Funds International Equities Mutual Funds [Member] |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | United States | Common collective trusts measured at net asset value | Pooled Investment Funds Common Collective Trusts |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 89,275 | 78,256 |
Pension Benefits | Foreign Retirement Plans |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 212,617 | 189,455 | 163,746
Pension Benefits | Foreign Retirement Plans | Fair Value | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 714 | 691 |
Pension Benefits | Foreign Retirement Plans | Fair Value | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 659 | 131 |
Pension Benefits | Foreign Retirement Plans | Fair Value | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 12,579 | 10,706 |
Pension Benefits | Foreign Retirement Plans | Fair Value | Debt Securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 575 | 663 |
Pension Benefits | Foreign Retirement Plans | Fair Value | Pooled investment funds Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 639 | 582 |
Pension Benefits | Foreign Retirement Plans | Level 1 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 2,482 | 2,050 |
Pension Benefits | Foreign Retirement Plans | Level 1 | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 714 | 691 |
Pension Benefits | Foreign Retirement Plans | Level 1 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 659 | 131 |
Pension Benefits | Foreign Retirement Plans | Level 1 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 1 | Debt Securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 470 | 646 |
Pension Benefits | Foreign Retirement Plans | Level 1 | Pooled investment funds Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 639 | 582 |
Pension Benefits | Foreign Retirement Plans | Level 2 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 12,684 | 10,723 |
Pension Benefits | Foreign Retirement Plans | Level 2 | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 2 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 2 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 12,579 | 10,706 |
Pension Benefits | Foreign Retirement Plans | Level 2 | Debt Securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 105 | 17 |
Pension Benefits | Foreign Retirement Plans | Level 2 | Pooled investment funds Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 3 |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 3 | Equity securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 3 | Cash and cash equivalents |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 3 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 3 | Debt Securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Level 3 | Pooled investment funds Mutual funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Pension Benefits | Foreign Retirement Plans | Common collective trusts measured at net asset value | Pooled investment funds Equity securities - international companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 13,062 | 13,074 |
Pension Benefits | Foreign Retirement Plans | Common collective trusts measured at net asset value | Pooled investment funds Equity Securities International companies |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 67,593 | 60,945 |
Pension Benefits | Foreign Retirement Plans | Common collective trusts measured at net asset value | Pooled investment funds Debt securities |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 77,766 | 67,094 |
Pension Benefits | Foreign Retirement Plans | Common collective trusts measured at net asset value | Pooled investment funds Diversified growth funds |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 39,030 | 35,569 |
Postretirement Benefits | United States |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 21,372 | 22,092 | $ 22,378
Postretirement Benefits | United States | Fair Value | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 21,372 | 22,092 |
Postretirement Benefits | United States | Level 1 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 0 | 0 |
Postretirement Benefits | United States | Level 2 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | 21,372 | 22,092 |
Postretirement Benefits | United States | Level 3 | Insurance contract |  |  |
Defined Benefit Plan Disclosure [Line Items] |  |  |
Fair value of plan assets | $ 0 | $ 0 |

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