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Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Taxes [Abstract]
Federal statutory tax rate	21.00%	21.00%	21.00%
Federal tax credits	(20.50%)	(13.40%)	(16.70%)
State and local taxes, net of federal tax benefit	10.10%	6.50%	6.50%
Flow through depreciation and cost basis differences	(4.90%)	1.50%	1.50%
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amortization, Percent	(4.70%)	(3.70%)	(4.10%)
Other	(1.00%)	(0.70%)	(0.80%)
Effective tax rate	0.00%	11.20%	7.40%

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- Definition

Income Taxes [Abstract]

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No definition available.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 12
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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to amortization.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to depreciation.

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to other tax credits.

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