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Income Taxes (Reconciliation Of U.S. Federal Statutory Rate To Effective Income Tax Rate) (Details) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Income Tax Disclosure [Abstract] |  |  |
Federal statutory rate | 21.00% | 21.00% | 21.00%
State taxes, net of federal tax | 1.70% | 2.40% | 2.10%
Foreign operations | 0.70% | 1.70% | (0.90%)
Research tax credit | (1.70%) | (1.70%) | (1.50%)
Foreign-derived intangible tax benefit | (0.40%) | (2.10%) | (2.40%)
U.S. minimum tax on foreign income | 0.50% | 1.00% | 1.50%
Uncertain tax positions | (1.70%) | 0.80% | 0.70%
Taxes applicable to prior years | (1.40%) | (0.30%) | (0.70%)
Change in U.S. tax rate | (0.00%) | (0.00%) | (2.00%)
Other items and adjustments | (0.40%) | 0.50% | 1.30%
Effective income tax rate | 18.30% | 23.30% | 19.10%

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- Definition Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by multiplying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to the deduction for the foreign derived intangible income deduction. + References No definition available. + Details
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