Represents the term of the warrants.

No definition available.

Name:	pgrx_ClassOfWarrantOrRightTerm
Namespace Prefix:	pgrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum voting power of warrants together with other shares held by the warrantholders expressed as a percentage of the total voting power of the outstanding common stock.

+ References

No definition available.

+ Details

Name:	pgrx_ClassOfWarrantOrRightVotingPowerOfWarrantsTogetherWithOtherSharesHeldExpressedAsPercentageOfTotalVotingPowerOfOutstandingCommonStockMaximum
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the direct or indirect ownership of the entity's common equity of the voting power of the outstanding shares of voting stock required before liquidation of stock.

+ References

No definition available.

+ Details

Name:	pgrx_DirectOrIndirectOwnershipInCommonEquityAsMinimumPercentageOfVotingPowerOfOutstandingSharesOfVotingStockRequiredBeforeStockLiquidation
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the consideration in the form of liquidation preference as a market capitalization cap percentage.

+ References

No definition available.

+ Details

Name:	pgrx_MarketCapitalizationCapPercentageForPreferredStockLiquidationPreferenceAsConsideration
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the minimum quantity of potash that has first been shipped for delivery.

+ References

No definition available.

+ Details

Name:	pgrx_MinimumQuantityOfPotashThatHasFirstBeenShippedForDelivery
Namespace Prefix:	pgrx_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage of gross revenue.

+ References

No definition available.

+ Details

Name:	pgrx_PercentageOfGrossRevenue
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the percentage at which dividends will accrue on preferred stock in case shareholder's approval for conversion is not obtained at the annual general meeting of the entity.

+ References

No definition available.

+ Details

Name:	pgrx_PreferredStockDividendRateAccrualPercentage
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the maximum voting power of all common stock and preferred stock held by the preferred stockholders expressed as a percentage of the outstanding voting power.

+ References

No definition available.

+ Details

Name:	pgrx_PreferredStockVotingPowerOfAllCommonStockAndPreferredStockHeldExpressedAsPercentageOfOutstandingVotingPowerMaximum
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the period for dividend payment following the month in which a specified quantity of potash has first been shipped for delivery.

+ References

No definition available.

+ Details

Name:	pgrx_TemporaryEquityPeriodForDividendPaymentFollowingMonthInWhichSpecifiedQuantityOfPotashHasFirstBeenShippedForDelivery
Namespace Prefix:	pgrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period for redemption by holder of security classified as temporary equity following the month in which a specified quantity of potash has first been shipped for delivery.

+ References

No definition available.

+ Details

Name:	pgrx_TemporaryEquityPeriodForRedemptionByHolderFollowingMonthInWhichSpecifiedQuantityOfPotashHasFirstBeenShippedForDelivery
Namespace Prefix:	pgrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the period for redemption by issuer of security classified as temporary equity.

+ References

No definition available.

+ Details

Name:	pgrx_TemporaryEquityPeriodForRedemptionByIssuer
Namespace Prefix:	pgrx_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage rate used to calculate dividend payments on preferred stock classified as temporary equity.

+ References

No definition available.

+ Details

Name:	pgrx_TemporaryEquityPreferredStockDividendRatePercentage
Namespace Prefix:	pgrx_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The exercise price of each class of warrants or rights outstanding.

+ References

Reference 1: 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.(i)(4))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Subparagraph 4

-Article 4

+ Details

Name:	us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	instant

- Definition

The specified number of securities that each class of warrants or rights outstanding give the holder the right but not the obligation to purchase from the issuer at a specific price, on or before a certain date.

+ References

Reference 1: 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.(i)(2))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph i

-Subparagraph 2

-Article 4

+ Details

Name:	us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 30

-Article 5

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The value of the financial instrument(s) that the original debt is being converted into in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4304-108586

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 32

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4332-108586

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The number of shares issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or payments in the period.

+ References

+ Details

Name:	us-gaap_DebtConversionConvertedInstrumentSharesIssued1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents the conversion ratio used in the calculation of a stock split.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Stock Split

-URI http://asc.fasb.org/extlink&oid=6525746

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 4

-Subparagraph (SAB TOPIC 4.C)

-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187143-122770

+ Details

Name:	us-gaap_StockholdersEquityNoteStockSplitConversionRatio
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The per share liquidation preference (or restrictions) of stock classified as temporary equity that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share. 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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_TemporaryEquityLiquidationPreferencePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.27(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 28

-Subparagraph b

-Article 5

+ Details

Name:	us-gaap_TemporaryEquitySharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Subsequent Events (Details) (USD $) In Thousands, except Share data, unless otherwise specified	35 Months Ended		3 Months Ended		0 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended				0 Months Ended	3 Months Ended		0 Months Ended			0 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2013 Buffalo	Aug. 01, 2012 Buffalo	Apr. 15, 2013 Buffalo First Extension Agreement	Jun. 30, 2013 Buffalo First Extension Agreement	Apr. 15, 2013 Karlsson Group First Extension Agreement	Jun. 30, 2013 Karlsson Group First Extension Agreement	Jun. 30, 2013 Karlsson Group Promissory notes	May 02, 2013 Unsecured subordinated promissory notes Very Hungry and the Scott Reiman 1991 Trust	Aug. 14, 2013 Subsequent Events	Aug. 14, 2013 Subsequent Events Redeemable Preferred Stock t	Jun. 30, 2013 Subsequent Events Warrant	Aug. 14, 2013 Subsequent Events Warrant	Aug. 14, 2013 Subsequent Events Buffalo	Aug. 14, 2013 Subsequent Events Buffalo Redeemable Preferred Stock	Aug. 14, 2013 Subsequent Events Buffalo Warrant	Aug. 14, 2013 Subsequent Events Buffalo Management and affiliates Redeemable Preferred Stock	Jul. 10, 2013 Subsequent Events Unsecured subordinated promissory notes Very Hungry and the Scott Reiman 1991 Trust	Jul. 10, 2013 Subsequent Events Unsecured subordinated promissory notes Very Hungry and the Scott Reiman 1991 Trust Public Offering	Dec. 31, 2014 Subsequent Events Unsecured subordinated promissory notes Very Hungry and the Scott Reiman 1991 Trust Public Offering Forecast	Jun. 15, 2014 Subsequent Events Unsecured subordinated promissory notes Very Hungry and the Scott Reiman 1991 Trust Public Offering Forecast	Dec. 15, 2013 Subsequent Events Unsecured subordinated promissory notes Very Hungry and the Scott Reiman 1991 Trust Public Offering Forecast
Subsequent Events
Amount of debt exchanged	$ 9,493																		$ 5,500
Number of senior mandatorily convertible preferred stock shares issued for exchange of unsecured subordinated promissory notes															15,000,000				5,500,000
Exercise price (in dollars per share)				$ 2.60						$ 0.30			$ 0.07	$ 0.144						$ 0.12
Reverse stock split																				50
Preferred stock dividends accrual (as a percent)																					30.00%	25.00%	20.00%
Maximum voting power of all common stock and preferred stock held as a percentage of outstanding voting power																				19.99%
Percentage of gross revenue			1.00%		2.00%	1.00%	1.00%	2.00%	1.00%
Number of shares of redeemable preferred stock issued																15,000,000
Exercise period													5 years
Number of common stock that can be purchased against warrants (in shares)				2,620,454													50,264,174
Liquidation preference (in dollars per share)												$ 1.00
Market capitalization cap percentage for liquidation preference												10.00%
Direct or indirect ownership of the entity's common equity of the voting power of the outstanding shares of voting stock before liquidation of stock																		50.00%
Annual rate for dividend accrual (as a percent)												8.00%
Period for dividend payment following the month in which a specified quantity of potash has first been shipped for delivery at Holbrook, Arizona facility												6 months
Minimum quantity of potash that has first been shipped for delivery at Holbrook, Arizona facility (in tonnes)												50,000
Period for redemption by issuer of redeemable preferred stock												3 years
Period for redemption by holder of redeemable preferred stock following the month in which a specified quantity of potash has first been shipped for delivery at Holbrook, Arizona facility												3 years 6 months
Maximum voting power of warrants together with other shares held as a percentage of total voting power of the outstanding common stock														19.99%			19.99%
Common stock outstanding (in shares)	115,119,415	72,595,718									115,194,415