Real Estate Summary of Real Estate Investments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Real Estate Properties [Line Items]
Construction in progress	$ 67,389		$ 32,183
Total Real estate, at cost	1,995,417		1,938,676
Accumulated depreciation	(318,581)		(270,494)
Net real estate	1,676,836		1,668,182
Total Retail
Real Estate Properties [Line Items]
Net real estate	651,707		669,177
Total Office
Real Estate Properties [Line Items]
Net real estate	790,153		759,203
Total Multifamily
Real Estate Properties [Line Items]
Net real estate	35,349		36,391
Total Mixed-Use
Real Estate Properties [Line Items]
Net real estate	199,627		203,411
Real Estate Investment
Real Estate Properties [Line Items]
Land	493,420	[1]	493,296	[1]
Buildings	1,282,580		1,263,120
Land improvements	52,793		52,763
Tenant improvements	99,362		92,382
Furniture, fixtures, and equipment	16,568		16,255
Construction in progress	50,694		20,860
Total Real estate, at cost	1,995,417		1,938,676
Accumulated depreciation	(318,581)		(270,494)
Net real estate	1,676,836		1,668,182
Real Estate Investment | Total Retail
Real Estate Properties [Line Items]
Land	248,008		247,884
Buildings	499,091		497,922
Land improvements	39,892		39,882
Tenant improvements	46,649		46,393
Furniture, fixtures, and equipment	489		486
Construction in progress	2,673		1,903
Total Real estate, at cost	836,802		834,470
Accumulated depreciation	(185,095)		(165,293)
Net real estate	651,707		669,177
Real Estate Investment | Total Office
Real Estate Properties [Line Items]
Land	150,300		150,300
Buildings	618,077		600,146
Land improvements	7,528		7,528
Tenant improvements	51,016		44,232
Furniture, fixtures, and equipment	517		1,124
Construction in progress	46,727		18,698
Total Real estate, at cost	874,165		822,028
Accumulated depreciation	(84,012)		(62,825)
Net real estate	790,153		759,203
Real Estate Investment | Total Multifamily
Real Estate Properties [Line Items]
Land	18,477		18,477
Buildings	42,270		41,968
Land improvements	3,010		2,990
Tenant improvements	0		0
Furniture, fixtures, and equipment	5,482		5,082
Construction in progress	19		1
Total Real estate, at cost	69,258		68,518
Accumulated depreciation	(33,909)		(32,127)
Net real estate	35,349		36,391
Real Estate Investment | Total Mixed-Use
Real Estate Properties [Line Items]
Land	76,635		76,635
Buildings	123,142		123,084
Land improvements	2,363		2,363
Tenant improvements	1,697		1,757
Furniture, fixtures, and equipment	10,080		9,563
Construction in progress	1,275		258
Total Real estate, at cost	215,192		213,660
Accumulated depreciation	(15,565)		(10,249)
Net real estate	$ 199,627		$ 203,411

[1] Land related to held for development and construction in progress is included in the Held for Development and Construction in Progress classifications on the consolidated balance sheets.