Income Taxes - Income Tax Temporary Differences Table (details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Credit carryforwards	$ 14	$ 14
Net current deferred income tax assets	14us-gaap_DeferredTaxAssetsGrossCurrent	14us-gaap_DeferredTaxAssetsGrossCurrent
Depreciable property	(3,240)	(38,528)
Credit carryforwards	512us-gaap_TaxCreditCarryforwardAmount	527us-gaap_TaxCreditCarryforwardAmount
Other intangible assets	(1,450)	0
Other	7us-gaap_DeferredTaxLiabilitiesOther	3us-gaap_DeferredTaxLiabilitiesOther
Net long-term deferred income tax liabilities	(4,171)	(37,998)
Total net deferred income tax liabilities	$ (4,157)us-gaap_DeferredTaxLiabilities	$ (37,984)us-gaap_DeferredTaxLiabilities

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards expected to be realized or consumed within one year or operating cycle, if longer.

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Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards, net of deferred tax liability attributable to taxable temporary differences expected to be realized or consumed after one year (or the normal operating cycle, if longer).

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Amount of deferred tax liability attributable to taxable temporary differences net of deferred tax asset attributable to deductible temporary differences and carryforwards after valuation allowances.

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Amount of deferred tax liability attributable to taxable temporary differences from intangible assets other than goodwill.

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Amount of deferred tax liability attributable to taxable temporary differences not separately disclosed.

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Amount of deferred tax liability attributable to taxable temporary differences from property, plant, and equipment.

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The amount of the tax credit carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Amount of deferred tax asset, before valuation allowance, attributable to deductible other tax carryforwards.

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