| **Subsequent Events (Details) (USD $)Share data in Thousands, except Per Share data, unless otherwise specified**  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
|--------------------------------------------------------------------------------------------------------------------|----------------|----------------|-----------------|
||
| **Subsequent Events [Abstract]**                                                                                   |           |           |            |   |   |
| Common Stock sold in public offering (in shares)                                                                   | 9,775          | 8,750          | 9,800           |   |   |
| Common stock offering price                                                                                        |           | $ 4.60         | $ 4.40          |   |   |
| Proceeds from public offering of common stock, net of underwriting discounts and commissions and offering expenses | $ 40,100,000   | $ 37,500,000   | $ 40,078,000    | $ 23,348,000 | $ 0 |
| Shelf registration established                                                                                     |           | 150,000,000    |            |   |   |
| Superseded registration                                                                                            |           | $ 31,700,000   |            |   |   |

| X                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Public offering price per share
+ References
No definition available.
+ Details**Name:**pgnx_CommonStockOfferingPrice**Namespace Prefix:**pgnx_**Data Type:**num:perShareItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of common stock sold in public offering
+ References
No definition available.
+ Details**Name:**pgnx_CommonStockSoldInPublicOfferingInShares**Namespace Prefix:**pgnx_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow associated with the amount received from entity's offering of stock to the public.
+ References
No definition available.
+ Details**Name:**pgnx_ProceedsFromPublicOfferingOfCommonStockNetOfUnderwritingDiscountsAndCommissionsAndOfferingExpenses**Namespace Prefix:**pgnx_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Shelf registration established
+ References
No definition available.
+ Details**Name:**pgnx_ShelfRegistrationEstablished**Namespace Prefix:**pgnx_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Superseded registration
+ References
No definition available.
+ Details**Name:**pgnx_SupersededRegistration**Namespace Prefix:**pgnx_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                            |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_SubsequentEventsAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |