Net Income per Share (Net Income Per Basic and Diluted Share) (Parentheticals) (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share [Abstract]
Estimated tax on interest expense on convertible notes	$ 0	$ 13,000	$ 0

The estimated tax on interest expense recognized in the period associated with any convertible debt.

No definition available.

Name:	pdli_EstimatedTaxOnConvertibleNoteInterestExpense
Namespace Prefix:	pdli_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration