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Income Taxes (Narrative) (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Income Tax Contingency [Line Items] |  |  |  |
Federal tax rate | 21.00% | 21.00% | 21.00% | 35.00%
Tax Cuts and Jobs Act of 2017, maximum operating loss carryforwards percentage | 80.00% |  |  |
Interest or penalties recorded in income statement | $ 0 | $ 0 | $ 0 |
Amounts accrued for interest or penalties | 0 | $ 0 |  |
Domestic Country [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Operating loss carryforwards | 0 |  |  |
State And Local Jurisdiction [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Operating loss carryforwards | $ 0 |  |  |
Minimum [Member] | Domestic Country [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal income tax years currently open for audits | 2017 |  |  |
Minimum [Member] | State And Local Jurisdiction [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal income tax years currently open for audits | 2018 |  |  |
Maximum [Member] | Domestic Country [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal income tax years currently open for audits | 2020 |  |  |
Maximum [Member] | State And Local Jurisdiction [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal income tax years currently open for audits | 2020 |  |  |
Scenario, Plan [Member] |  |  |  |
Income Tax Contingency [Line Items] |  |  |  |
Federal tax rate | 21.00% |  |  |

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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 6.I.Fact.4) -URI http://asc.fasb.org/extlink&oid=116825942&loc=d3e330036-122817 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32687-109319 + Details
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- Definition Tax year that remains open to examination under enacted tax laws, in CCYY format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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- Definition Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32559-109319 + Details
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- Definition Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84230637&loc=d3e32718-109319 + Details
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