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Commitments and Contingencies (Details) - USD ($) $ in Millions | Feb. 18, 2021 | Dec. 31, 2020 | Dec. 31, 2019
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Loss Contingency, Estimate [Abstract] |  |  |
Accrual for legal proceedings and unasserted claims |  |  | $ 0
FCC license auction, percent of bid credit in each auction |  | 25.00% |
Maximum |  |  |
Loss Contingency, Estimate [Abstract] |  |  |
Accrual for legal proceedings and unasserted claims |  | $ 1 |
Subsequent event |  |  |
Loss Contingency, Estimate [Abstract] |  |  |
Commitment to purchase wireless spectrum licenses | $ 1,460 |  |

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- Definition Amount of loss contingency liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349 + Details
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