Equity and Capital Equity and Capital - Common Units (Details) $ in Millions	1 Months Ended
Sep. 30, 2019 USD ($) shares
Equity [Abstract]
Issuance of exchangeable operating partnership, units \| shares	396,531
Issuance of operating partnership, value \| $	$ 25.9

Issuance of exchangeable operating partnership units.

No definition available.

Name:	reg_IssuanceOfExchangeableOperatingPartnershipUnits
Namespace Prefix:	reg_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration