Note 4 - Fair Value Measurements - Summary of Activities in Financial Instruments With Level 3 Inputs (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Balance	$ 11,000	$ 16,800
Fair value change included in net loss	916	(5,800)
Payments	(8,016)
Balance	3,900	11,000
Changes in unrealized gains or losses for the period included in earnings (or changes in net assets) for liabilities held at the end of the reporting period	$ 916	$ (5,800)

Represents changes in unrealized gains or losses for period included in earnings or changes in net assets for liabilities held at end of reporting period.

No definition available.

+ Details

Name:	pgnx_ChangesInUnrealizedGainsOrLossesForPeriodIncludedInEarningsOrChangesInNetAssetsForLiabilitiesHeldAtEndOfReportingPeriod
Namespace Prefix:	pgnx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents fair value change to contingent consideration included in net loss.

+ References

No definition available.

+ Details

Name:	pgnx_FairValueChangeToContingentConsiderationIncludedInNetLoss
Namespace Prefix:	pgnx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant