Investments in Real Estate Partnerships - Schedule of Investments in Real Estate Partnerships (Details) (USD $)	12 Months Ended								12 Months Ended												9 Months Ended	12 Months Ended			12 Months Ended				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 GRI - Regency, LLC [Member]	Dec. 31, 2012 GRI - Regency, LLC [Member]	Dec. 31, 2013 Macquarie Country Wide - Regency III, LLC [Member]	Dec. 31, 2012 Macquarie Country Wide - Regency III, LLC [Member]	Mar. 20, 2013 Macquarie Country Wide - Regency III, LLC [Member]	Dec. 31, 2013 Columbia Regency Retail Partners, LLC [Member]	Dec. 31, 2012 Columbia Regency Retail Partners, LLC [Member]	Dec. 31, 2013 Columbia Regency Partners II, LLC [Member]	Dec. 31, 2012 Columbia Regency Partners II, LLC [Member]	Dec. 31, 2013 Cameron Village, LLC [Member]	Dec. 31, 2012 Cameron Village, LLC [Member]	Dec. 31, 2013 RegCal, LLC [Member]	Dec. 31, 2012 RegCal, LLC [Member]	Dec. 31, 2013 Regency Retail Partners, LP [Member]	Dec. 31, 2012 Regency Retail Partners, LP [Member]	Dec. 31, 2013 US Regency Retail I, LLC [Member]	Dec. 31, 2012 US Regency Retail I, LLC [Member]	Sep. 30, 2013 BRE Throne Holdings LLC (BRET) [Member]	Dec. 31, 2013 BRE Throne Holdings LLC (BRET) [Member]	Dec. 31, 2012 BRE Throne Holdings LLC (BRET) [Member]	Jul. 25, 2012 BRE Throne Holdings LLC (BRET) [Member]	Dec. 31, 2013 Other Investments in Real Estate Partnerships [Member]	Dec. 31, 2012 Other Investments in Real Estate Partnerships [Member]	Dec. 31, 2013 Equity Method Investments [Member]	Dec. 31, 2012 Equity Method Investments [Member]	Dec. 31, 2011 Transaction Fee Income [Member]	Dec. 31, 2013 Corporate Joint Venture [Member]	Dec. 31, 2012 Corporate Joint Venture [Member]	Dec. 31, 2012 Lake Grove Commons [Member] Corporate Joint Venture [Member]	Dec. 31, 2012 Lake Grove Commons [Member] Corporate Joint Venture [Member] GRI - Regency, LLC [Member]	Dec. 31, 2013 Shoppes at Burnt Mills [Member] Corporate Joint Venture [Member]	Dec. 31, 2013 Shoppes at Burnt Mills [Member] Corporate Joint Venture [Member] Columbia Regency Partners II, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Effective Date of Acquisition																																Jan. 17, 2012		Jul. 23, 2013
Business Acquisition, Name of Acquired Entity																																Lake Grove Commons		Shoppes of Burnt Mills
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2013
Business Acquisition, Description of Acquired Entity																																	GRIR		Columbia II
Proceeds from Sale of Real Estate																							$ 321,000,000
Provision for impairment	6,000,000	74,816,000	15,883,000																				18,100,000
Ownership Percentage				0.00%	0.00%	0.00%	0.00%	24.95%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%	0.00%		0.00%	0.00%		0.00%	0.00%						0.00%		0.00%
Proceeds from Limited Partnership Investments																						47,500,000
Investments in real estate partnerships	358,849,000	442,927,000		250,118,000	272,044,000	0	29,000		16,735,000	17,200,000	8,797,000	8,660,000	16,678,000	16,708,000	15,576,000	15,602,000	1,793,000	15,248,000	1,391,000	2,173,000		0	48,757,000	47,500,000	47,761,000	46,506,000
Preferred Stock, Dividend Rate, Percentage																					10.50%
Revenue from Related Parties	24,153,000	25,423,000	28,980,000																										5,000,000
Total Assets of the Partnership	2,939,599,000	3,434,954,000		1,870,660,000	1,939,659,000	0	60,496,000		204,759,000	210,490,000	295,829,000	326,649,000	103,805,000	102,930,000	159,255,000	164,106,000	9,325,000	323,406,000	118,865,000	123,053,000		0	0		177,101,000	184,165,000
Net Income (Loss) of the Partnership	71,050,000	79,264,000	45,260,000	31,705,000	23,357,000	213,000	(75,000)		8,605,000	42,399,000	6,290,000	1,467,000	2,198,000	2,021,000	1,300,000	2,160,000	9,234,000	407,000	2,387,000	1,484,000		4,499,000	2,211,000		4,619,000	3,833,000
Income (Loss) from Equity Method Investments	31,718,000	23,807,000	9,643,000	12,789,000	9,311,000	53,000	(22,000)		1,727,000	8,480,000	1,274,000	290,000	662,000	596,000	332,000	540,000	7,749,000	297,000	487,000	297,000		4,499,000	2,211,000		2,146,000	1,807,000
Notes payable (note 8)																											534,100,000	597,400,000
Significant Acquisitions and Disposals, Acquisition Costs or Sale Proceeds																														13,600,000	164,600,000	72,500,000		13,600,000
Noncash or Part Noncash Acquisition, Debt Assumed																														7,496,000	76,313,000	31,813,000		7,496,000
Finite-lived Intangible Assets Acquired																														8,438,000	8,002,000	5,397,000		8,438,000
Acquired Finite Lived Intangible Liability Amount																														$ 332,000	$ 5,062,000	$ 4,342,000		$ 332,000
Business Acquisition Location, City and State																																Lake Grove, NY		Silver Spring, MD
Business Acquisition, Property type																																Operating		Operating