Fair Value Measurements (Fair Value Measurements on a Nonrecurring Basis) (Details) - PREIT - Nonrecurring $ in Thousands	Sep. 30, 2017 USD ($)
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total Assets, Nonrecurring	$ 65,563
Level 1
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total Assets, Nonrecurring	$ 65,563

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

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