Represents the amount of gain or loss recognized from the conversion of convertible debt during the period.

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Represents the probability percentage of a change in control upon a call feature being triggered.

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Represents the probability of occurrence of other features in the combined embedded derivative in the event of a change in control.

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Represents the probability percentage of occurrence upon other features being triggered.

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The minimum equity proceeds condition for automatic conversion of convertible notes.

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The conversion price percentage of convertible notes.

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The multiplier used when the Company has the option to prepay the Convertible Notes.

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Represent discount on convertible debt.

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Represents the amount written off during the period related to the embedded derivative liability.

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The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Including the current and noncurrent portions, carrying amount of debt identified as being convertible into another form of financial instrument (typically the entity's common stock) as of the balance sheet date, which originally required full repayment more than twelve months after issuance or greater than the normal operating cycle of the company.

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Carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Convertible Notes Payable, excluding current portion. Convertible Notes Payable is a written promise to pay a note which can be exchanged for a specified amount of another, related security, at the option of the issuer and the holder.

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Amount of a favorable spread to a debt holder between the amount of debt being converted and the value of the securities received upon conversion. This is an embedded conversion feature of convertible debt issued that is in-the-money at the commitment date.

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The price per share of the conversion feature embedded in the debt instrument.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

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For an unclassified balance sheet, the amount as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain. Such amount is before the consideration of accumulated amortization.

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Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

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The cash inflow from the issuance of common stock, preferred stock, treasury stock, stock options, and other types of equity.

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Price of a single share of a number of saleable stocks of a company.

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The number of securities classified as temporary equity that have been sold (or granted) to the entity's shareholders. Securities issued include securities outstanding and securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

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Note 5 - Convertible Notes (Details) (USD $)	0 Months Ended		12 Months Ended		0 Months Ended
Note 5 - Convertible Notes (Details) (USD $)	Sep. 04, 2013	Sep. 04, 2013	Dec. 31, 2014	Dec. 31, 2013	May 13, 2014	Dec. 31, 2012
Note 5 - Convertible Notes (Details) [Line Items]
Convertible Debt	$ 4,300,000us-gaap_ConvertibleDebt	$ 4,300,000us-gaap_ConvertibleDebt
Debt Instrument, Interest Rate, Stated Percentage	8.00%	8.00%
Deferred Finance Costs, Gross			18,000us-gaap_DeferredFinanceCostsGross	18,000us-gaap_DeferredFinanceCostsGross		0us-gaap_DeferredFinanceCostsGross
Discount on Convertible Debt		10,000prto_DiscountOnConvertibleDebt
Embedded Derivative, Fair Value of Embedded Derivative Liability	1,400,000	1,400,000	0	1,400,000
Debt Instrument, Unamortized Discount	1,400,000	1,400,000
Convertible Notes Automatic Conversion Condition, Equity Proceeds Minimum			7,000,000
Convertible Notes Conversion Percentage of Cash Price Per Share			75.00%
Convertible Notes Repayment Factor			1.5prto_ConvertibleNotesRepaymentFactor
Debt Instrument, Convertible, Beneficial Conversion Feature	7,000,000
Convertible Debt Probability of Change in Control Percentage	15.00%			0.00%
Convertible Debt Probability Of Occurrence Percentage Other Features	0.00%			0.00%
Series C Preferred Stock [Member]
Note 5 - Convertible Notes (Details) [Line Items]
Debt Instrument, Convertible, Conversion Price (in Dollars per share)			$ 1.15
Temporary Equity, Shares Issued (in Shares)			0	13,202,932
Series D Preferred Stock [Member]
Note 5 - Convertible Notes (Details) [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Liability					1,500,000
Debt Instrument, Convertible, Conversion Price (in Dollars per share)					$ 0.4414
Proceeds from Issuance or Sale of Equity					25,000,000
Share Price (in Dollars per share)					$ 0.588656
Temporary Equity, Shares Issued (in Shares)			0	0	52,813,827
Conversion of Stock, Shares Issued (in Shares)					10,344,201
Convertible Notes Payable, Noncurrent					4,600,000
EmbeddedDerivativeEmbeddedDerivativeLiabilityWriteOff					1,500,000
Convertible Debt, Gain (Loss) Recognized					0
Convertible Debt [Member]
Note 5 - Convertible Notes (Details) [Line Items]
Debt Instrument, Term			7 months
Minimum [Member]
Note 5 - Convertible Notes (Details) [Line Items]
Convertible Debt Probability of Occurrence Percentage	85.00%
Maximum [Member]
Note 5 - Convertible Notes (Details) [Line Items]
Convertible Debt Probability of Occurrence Percentage				100.00%
Other Current Assets [Member]
Note 5 - Convertible Notes (Details) [Line Items]
Deferred Finance Costs, Gross	$ 36,000	$ 36,000