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Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items] |  |  |
Unrecognized tax benefits, income tax penalties and interest expense | $ 0 | $ 0 | $ 0
Change in carrying amount of goodwill during period | 0 |  |
COVID-19 [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Deferred net benefit to customers | $ 2,800,000 |  |
Restricted Stock [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Award vesting period | 3 years |  |
Total Shareholder Return Market-Based Awards and Performance Awards [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Award vesting period | 3 years |  |
Dividend component liability, current | $ 800,000 | $ 900,000 |
Total Shareholder Return Market-Based Awards and Performance Awards [Member] | Minimum [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Common stock issued range, percent of the performance shares granted | 0.00% |  |
Total Shareholder Return Market-Based Awards and Performance Awards [Member] | Maximum [Member] |  |  |
Summary Of Significant Accounting Policies [Line Items] |  |  |
Common stock issued range, percent of the performance shares granted | 200.00% |  |

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