Organization and Significant Accounting Policies - Organization and Principles of Consolidation (Details) $ / shares in Units, $ in Thousands			9 Months Ended
	Aug. 18, 2023 $ / shares	May 17, 2023	Sep. 30, 2023 USD ($) RetailShoppingCenter $ / shares	Dec. 31, 2022 USD ($) $ / shares
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Unsecured public and private notes | $			$ 200,000
Tenant and other receivables | $			$ 199,439	$ 188,863
Conversion of Stock, Description			The combined company continues to trade under the ticker symbol “REG” on the National Association of Securities Dealers Automated Quotations (the “NASDAQ”). The closing of the mergers completed on August 18, 2023 and each share of Urstadt Biddle’s common stock, par value $0.01 per share (“Urstadt Biddle common stock”), class A common stock, par value $0.01 per share (“Urstadt Biddle Class A common stock” and, together with Urstadt Biddle common stock, the “Urstadt Biddle common shares”), 6.25% Series H Cumulative Redeemable Preferred Stock and 5.875% Series K Cumulative Redeemable Preferred Stock converted into one equivalent share in UB Sub I, with respect to each class, subject to limited exceptions set forth in the merger agreement. Immediately thereafter, on August 18, 2023, each share of UB Sub I’s common stock, par value $0.01 per share, and class A common stock, par value $0.01 per share, converted into 0.347 of a share of common stock, par value $0.01 per share, of common stock of the Parent Company, without interest and subject to certain adjustments, subject to limited exceptions set forth in the merger agreement, and each share of UB Sub I’s 6.25% Series H Cumulative Redeemable Preferred Stock and 5.875% Series K Cumulative Redeemable Preferred Stock converted into one share of newly issued Parent Company 6.25% Series A Cumulative Redeemable Preferred Stock (“Parent Company Series A preferred stock”) and 5.875% Series B Cumulative Redeemable Preferred Stock (“Parent Company Series B preferred stock”), respectively (collectively referred to as the “Preferred Stock”).
Common stock, par value per share			$ 0.01	$ 0.01
Merger Agreement [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Merger agreement date		May 17, 2023
Merger One [Member] | Urstadt Biddle Common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Common stock, par value per share			0.01
Merger One [Member] | Urstadt Biddle Class A common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Common stock, par value per share			$ 0.01
Merger One [Member] | 6.25% Series H Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Debt instrument interest rate stated percentage			6.25%
Merger One [Member] | 5.875% Series K Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Debt instrument interest rate stated percentage			5.875%
Merger One [Member] | Common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Stock conversion ratio			1
Merger Two [Member] | Urstadt Biddle Class A common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Common stock, par value per share	$ 0.01
Merger Two [Member] | UB Sub I common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Common stock, par value per share	$ 0.01
Merger Two [Member] | 6.25% Series H Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Debt instrument interest rate stated percentage	6.25%
Merger Two [Member] | 5.875% Series K Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Debt instrument interest rate stated percentage	5.875%
Merger Two [Member] | Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Stock conversion ratio	1
Merger Two [Member] | Series A Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Debt instrument interest rate stated percentage	6.25%
Merger Two [Member] | Series B Cumulative Redeemable Preferred Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Debt instrument interest rate stated percentage	5.875%
Merger Two [Member] | Common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Stock conversion ratio	0.347
UBP Acquisition [Member] | Common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Common stock, par value per share			$ 0.01
Management, transaction, and other fee [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Tenant and other receivables | $			$ 15,900	$ 16,400
Operating Partnership [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Ownership percentage of outstanding common partnership units			99.40%
Wholly Owned Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of real estate properties | RetailShoppingCenter			379
Partially Owned Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of real estate properties | RetailShoppingCenter			120
Consolidated Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of real estate properties | RetailShoppingCenter			18
Unconsolidated Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of real estate properties | RetailShoppingCenter			102