Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Operating Revenue	$ 7,261us-gaap_SalesRevenueNet	$ 6,514us-gaap_SalesRevenueNet
Operating Expenses:
Maintenance of way and structures	1,533pwx_MaintenanceOfWayAndStructures	1,352pwx_MaintenanceOfWayAndStructures
Maintenance of equipment	762	912
Transportation	2,792	2,471
General and administrative	1,382us-gaap_GeneralAndAdministrativeExpense	1,238us-gaap_GeneralAndAdministrativeExpense
Depreciation	876us-gaap_Depreciation	900us-gaap_Depreciation
Taxes, other than income taxes	733	657
Car hire, net	383us-gaap_FreightCosts	226us-gaap_FreightCosts
Employee retirement plans	57	57
Track usage fees	40pwx_TrackUsageFees	29pwx_TrackUsageFees
Total Operating Expenses	8,558us-gaap_CostsAndExpenses	7,842us-gaap_CostsAndExpenses
Loss from Operations	(1,297)	(1,328)
Other income	7us-gaap_OtherOperatingIncome	10us-gaap_OtherOperatingIncome
Loss from operations prior to income taxes	(1,290)	(1,318)
Provision from Income Tax (Benefit)	(447)us-gaap_IncomeTaxExpenseBenefit	(641)us-gaap_IncomeTaxExpenseBenefit
Net Loss	(843)us-gaap_NetIncomeLoss	(677)us-gaap_NetIncomeLoss
Preferred Stock Dividends	3	3
Net Loss Available to Common Shareholders	$ (846)	$ (680)
Basic and Diluted Loss Per Common Share	$ (0.17)us-gaap_EarningsPerShareBasicAndDiluted	$ (0.14)us-gaap_EarningsPerShareBasicAndDiluted
Weighted-Average Common Shares Outstanding
For basic	4,859,879	4,850,938
For diluted	4,859,879	4,850,938

Maintenance of way and structures.

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Track usage fees.

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The aggregate costs of keeping the property in good condition but that do not appreciably prolong the life or increase the value of the property.

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Total costs of sales and operating expenses for the period.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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Cost of freight-in, whether based on weight, negotiated freight rates and method of transportation (that is, rail, barge, truck, and so forth).

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The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

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

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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The total amount of other operating income, the components of which are not separately disclosed on the income statement, from items that are associated with the entity's normal revenue producing operation.

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The amount of pension and other (such as medical, dental and life insurance) postretirement benefit costs recognized during the period for (1) defined benefit plans (periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss) on assets, prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments) and for (2) defined contribution plans (to the extent that a plan's defined contributions to an individual's account are to be made for periods in which that individual renders services, the net cost for a period is the contribution called for in that period; if a plan calls for contributions for periods after an individual retires or terminates, the estimated cost is accrued during the employee's service period).

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The amount of preferred stock dividends that is an adjustment to net income apportioned to common stockholders.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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Cost incurred during the reporting period in transporting goods and services to customers. Includes freight-out costs.

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All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax.

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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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