Income Taxes - Tax Status of Dividends (Parenthetical) (Details)	12 Months Ended
Dec. 31, 2021
Income Tax Disclosure [Abstract]
Capital gain distribution	42.00%
Remaining capital gain distribution	58.00%

Allocation of remaining capital gain distribution percentage.

No definition available.

Name:	reg_AllocationOfRemainingCapitalGainDistributionPercentage
Namespace Prefix:	reg_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration