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Income Taxes (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2020 | Mar. 31, 2019 | Dec. 31, 2019
Operating Loss Carryforwards [Line Items] |  |  |
Current tax expense | $ 271 | $ 22 | $ 22
Deferred tax expense | 913 | 141 |
Income tax expense | 1,184 | 163 |
Cash paid for income taxes | 44 | 0 |
Effective income tax reconciliation, decrease in valuation allowance |  | $ 203 |
Domestic Tax Authority |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Operating loss carryforwards |  |  | $ 83,270
Operating loss carryforward expiration period |  |  | 18 years
State and Local Jurisdiction |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Operating loss carryforwards |  |  | $ 44,857
Minimum | State and Local Jurisdiction |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Operating loss carryforward expiration period |  |  | 8 years
Maximum | State and Local Jurisdiction |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Operating loss carryforward expiration period |  |  | 18 years
Plateau Excavation |  |  |
Operating Loss Carryforwards [Line Items] |  |  |
Effective income tax reconciliation, state income taxes | $ 332 |  |

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