Note 9 - Non-recourse Long-term Debt, Net - Future Principal and Interest Payments on Debt (Details) $ in Thousands	Dec. 31, 2018 USD ($)
2022	$ 19,560
Royalty-backed Loan [Member]
2019	5,688
2020	6,989
2021	13,125
Total payments	$ 45,362

Amount, before unamortized (discount) premium and accrued interest, of long-term debt payments.

No definition available.

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Amount of long-term debt payable and accrued interest maturing in the next fiscal year following the latest fiscal year.

No definition available.

Name:	pgnx_LongtermDebtRepaymentsOfDebtInNextTwelveMonths
Namespace Prefix:	pgnx_
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Amount of long-term debt payable and accrued interest maturing in the fourth fiscal year following the latest fiscal year.

No definition available.

Name:	pgnx_LongtermDebtRepaymentsOfDebtInYearFour
Namespace Prefix:	pgnx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of long-term debt payable and accrued interest maturing in the third fiscal year following the latest fiscal year.

No definition available.

Name:	pgnx_LongtermDebtRepaymentsOfDebtInYearThree
Namespace Prefix:	pgnx_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of long-term debt payable and accrued interest maturing in the second fiscal year following the latest fiscal year.

No definition available.

Name:	pgnx_LongtermDebtRepaymentsOfDebtInYearTwo
Namespace Prefix:	pgnx_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

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Namespace Prefix:
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Balance Type:
Period Type: