| **Revenue Recognition (Details) - USD ($) $ in Millions** | 1 Months Ended | 3 Months Ended |
|-----------------------------------------------------------|----------------|----------------|
||
| **Revenue Recognition [Abstract]**                        |           |           |   |
| Milestone Revenue from Fuji                               |           |           | $ 1.0 |
| Milestone Revenue from Salix                              |           | $ 40.0         |   |
| Subsequent Event [Member]                                 |           |           |   |
| **Subsequent Event [Line Items]**                         |           |           |   |
| Expected Future Milestone Receivable                      | $ 1.5          |           |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
We expect to receive a milestone payment as a result of an announcement that the first patient in a Phase 3 clinical trial was dosed and we are eligible for future milestone and royalty payments.
+ References
No definition available.
+ Details**Name:**pgnx_ExpectedFutureMilestoneReceivable**Namespace Prefix:**pgnx_**Data Type:**xbrli:monetaryItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Milestone Revenue from Fuji
+ References
No definition available.
+ Details**Name:**pgnx_MilestoneRevenueFromFuji**Namespace Prefix:**pgnx_**Data Type:**xbrli:monetaryItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Milestone Revenue from Salix
+ References
No definition available.
+ Details**Name:**pgnx_MilestoneRevenueFromSalix**Namespace Prefix:**pgnx_**Data Type:**xbrli:monetaryItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - References
No definition available.
+ Details**Name:**us-gaap_RevenueRecognitionAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.
+ References
No definition available.
+ Details**Name:**us-gaap_SubsequentEventLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |