Name:	dei_DocumentFiscalYearFocus
Namespace Prefix:	dei_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

[Line Items] for Business Acquisition, Pro Forma Information [Table]

No definition available.

Name:	reg_BusinessAcquisitionProFormaInformationLineItems
Namespace Prefix:	reg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Business Combination, Pro Forma Information, Expenses of Acquiree since Acquisition Date, Actual

No definition available.

Name:	reg_BusinessCombinationProFormaInformationExpensesofAcquireesinceAcquisitionDateActual
Namespace Prefix:	reg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Business Combination, Transaction Costs

No definition available.

Name:	reg_BusinessCombinationTransactionCosts
Namespace Prefix:	reg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463

Name:	us-gaap_BusinessAcquisitionProFormaEarningsPerShareBasic
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Name:	us-gaap_BusinessAcquisitionProFormaEarningsPerShareDiluted
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

The pro forma income from continuing operations before changes in accounting and extraordinary items, net of tax effect, for the period as if the business combination or combinations had been completed at the beginning of a period.

Name:	us-gaap_BusinessAcquisitionsProFormaIncomeLossFromContinuingOperationsBeforeChangesInAccountingAndExtraordinaryItemsNetOfTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

Name:	us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

Name:	us-gaap_BusinessAcquisitionsProFormaRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(1)
-URI http://asc.fasb.org/extlink&oid=56956515&loc=d3e1392-128463