Real Estate Summary of Real Estate Investments (Details) - USD ($) $ in Thousands		Dec. 31, 2016	Dec. 31, 2015
Real Estate Properties [Line Items]
Construction in progress		$ 50,498	$ 73,121
Total Real estate, at cost		2,301,006	2,246,028
Accumulated depreciation		(469,460)	(411,166)
Net real estate		1,831,546	1,834,862
Total Retail
Real Estate Properties [Line Items]
Net real estate		629,261	638,893
Total Office
Real Estate Properties [Line Items]
Net real estate		813,414	796,773
Real Estate Investment
Real Estate Properties [Line Items]
Land		490,459	490,494
Buildings		1,556,323	1,501,459
Land improvements		55,299	54,119
Tenant improvements		137,916	120,719
Furniture, fixtures, and equipment		16,656	15,065
Construction in progress	[1]	44,353	64,172
Total Real estate, at cost		2,301,006	2,246,028
Accumulated depreciation		(469,460)	(411,166)
Net real estate		1,831,546	1,834,862
Real Estate Investment | Total Retail
Real Estate Properties [Line Items]
Land		245,553	245,588
Buildings		522,032	500,075
Land improvements		40,736	40,203
Tenant improvements		61,323	54,993
Furniture, fixtures, and equipment		702	491
Construction in progress		2,805	20,817
Total Real estate, at cost		873,151	862,167
Accumulated depreciation		(243,890)	(223,274)
Net real estate		629,261	638,893
Real Estate Investment | Total Office
Real Estate Properties [Line Items]
Land		143,575	143,575
Buildings		697,558	665,431
Land improvements		8,777	8,273
Tenant improvements		74,747	63,880
Furniture, fixtures, and equipment		1,764	1,265
Construction in progress		40,123	41,669
Total Real estate, at cost		966,544	924,093
Accumulated depreciation		(153,130)	(127,320)
Net real estate		813,414	796,773
Real Estate Investment | Total Multifamily
Real Estate Properties [Line Items]
Land		24,696	24,696
Buildings		210,873	210,093
Land improvements		3,304	3,280
Tenant improvements		0	0
Furniture, fixtures, and equipment		8,421	7,638
Construction in progress		851	1,649
Total Real estate, at cost		248,145	247,356
Accumulated depreciation		(45,131)	(38,626)
Net real estate		203,014	208,730
Real Estate Investment | Total Mixed-Use
Real Estate Properties [Line Items]
Land		76,635	76,635
Buildings		125,860	125,860
Land improvements		2,482	2,363
Tenant improvements		1,846	1,846
Furniture, fixtures, and equipment		5,769	5,671
Construction in progress		574	37
Total Real estate, at cost		213,166	212,412
Accumulated depreciation		(27,309)	(21,946)
Net real estate		$ 185,857	$ 190,466

[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.