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Long-Term Debt (1.625% Senior Notes due 2029) (Details) - Senior Notes [Member] € in Millions, $ in Millions | Dec. 31, 2020 USD ($) | Jun. 12, 2020 USD ($) | Dec. 31, 2019 USD ($) | Jul. 17, 2019 USD ($) | Jul. 17, 2019 EUR (€)
--- | --- | --- | --- | --- | ---
1.625% Senior Notes Due 2029 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount | € |  |  |  |  | € 700
Long-term Debt | $ 849 |  | $ 774 | $ 779 |
3.375 Senior Notes Due 2030 |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Debt Instrument, Face Amount |  | $ 300 |  |  |
Long-term Debt | $ 296 |  | $ 0 |  |

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