Organization and Significant Accounting Policies - Organization and Principles of Consolidation (Details) $ / shares in Units, $ in Thousands		6 Months Ended
	May 17, 2023	Jun. 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 | $		$ 206,053	$ 188,863
Conversion of Stock, Description		The combined company will retain the Regency name and continue to trade under the ticker symbol “REG” on the National Association of Securities Dealers Automated Quotations (the “NASDAQ”). On the terms and subject to the conditions set forth in the merger agreement, which has been approved by the boards of directors of Regency Centers Corporation and UBP, at the effective time of the first merger (the “first merger effective time”), 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 will be 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, at the effective time of the second merger (the “second merger effective time”), 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, will be 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 will be 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.
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]
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] | 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] | 6.25% 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] | 5.875% 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] | 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] | Common Stock [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Stock conversion ratio		0.347
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 | $		$ 17,100	$ 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		310
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		108
Consolidated Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of real estate properties | RetailShoppingCenter		12
Unconsolidated Properties [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Number of real estate properties | RetailShoppingCenter		96