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Income Taxes (Tax Carryforwards) (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Operating Loss Carryforwards [Line Items] |  |
Deferred Tax Asset Balance, Gross | $ 387,372 | $ 290,474
Valuation Allowance | (19,191) | (18,445)
Total deferred tax assets | 368,181 | $ 272,029
Federal | Net Operating Loss | 2029-2032 |  |
Operating Loss Carryforwards [Line Items] |  |
Deferred Tax Asset Balance, Gross | 19,903 |
Valuation Allowance | (15,852) |
Total deferred tax assets | 4,051 |
Pre-Tax Earnings Necessary to Realize | 19,292 |
State | Net Operating Loss | 2023-2034 |  |
Operating Loss Carryforwards [Line Items] |  |
Deferred Tax Asset Balance, Gross | 15,783 |
Valuation Allowance | (3,339) |
Total deferred tax assets | 12,444 |
Pre-Tax Earnings Necessary to Realize | 1,346,109 |
State | Other Credits | 2023-2030 |  |
Operating Loss Carryforwards [Line Items] |  |
Deferred Tax Asset Balance, Gross | 12,733 |
Valuation Allowance | 0 |
Total deferred tax assets | $ 12,733 |

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