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v2.4.1.9

Income Taxes Schedule of Effective Income Tax Rate Reconciliation (Details) | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Income Taxes [Abstract] |  |  |
Federal statutory tax rate | 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate | 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate | 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate
Federal tax credits | (11.40%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther | (21.80%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther | (11.80%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCreditsOther
State and local taxes, net of federal tax benefit | 3.90%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes | 3.40%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes | 3.50%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance | 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance | 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance | 2.60%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance
Flow through depreciation and cost basis differences | (2.30%)us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepreciation | 2.80%us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepreciation | 2.40%us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseDepreciation
Other | 0.80%us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments | (2.60%)us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments | (0.60%)us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments
Effective tax rate | 26.00%us-gaap_EffectiveIncomeTaxRateContinuingOperations | 16.80%us-gaap_EffectiveIncomeTaxRateContinuingOperations | 31.10%us-gaap_EffectiveIncomeTaxRateContinuingOperations

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- Definition Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(h)(2)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 2 -Article 4 + Details
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- Definition Percentage of domestic federal statutory tax rate applicable to pretax income (loss). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 + Details
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- Definition 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 changes in the valuation allowance for deferred tax assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32687-109319 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 6.I) -URI http://asc.fasb.org/extlink&oid=34349781&loc=d3e330036-122817 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32698-109319 + Details
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