Note 3 - Property Acquisitions, Developments and Other Investments (Details) - Acquisition of Operating Properties ft² in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2015 USD ($) ft²		Dec. 31, 2014 USD ($) ft²
Business Acquisition [Line Items]
Purchase price, cash		$ 712,055	[1]	$ 510,052	[2]
Purchase price, debt assumed		807,591		702,550
Purchase price, other	[3]	252,467		229,635
Purchase price, total		$ 1,772,113		$ 1,442,237
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	7,519		7,104
Elmont Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1],[5]	$ 2,400
Purchase price, debt assumed	[5]	0
Purchase price, other	[3],[5]	3,358
Purchase price, total	[5]	$ 5,758
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]	13
Garden State Pavillion [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 16,300
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 16,300
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	111
Kimstone [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1],[5]	$ 513,513
Purchase price, debt assumed	[5]	637,976
Purchase price, other	[3],[5]	236,011
Purchase price, total	[5]	$ 1,387,500
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]	5,631
Copperfield Village [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 18,700
Purchase price, debt assumed		20,800
Purchase price, other	[3]	0
Purchase price, total		$ 39,500
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	165
Snowden Square [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 4,868
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 4,868
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	25
Dulles Town Crossing [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 4,830
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 4,830
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	9
Flagler Park [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 1,875
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 1,875
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	5
West Farms [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 6,200
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 6,200
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	24
Milleridge Inn [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 7,500
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 7,500
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	0
Woodgrove Festival [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 5,611
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 5,611
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	12
Montgomery Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1],[5]	$ 34,522
Purchase price, debt assumed	[5]	29,311
Purchase price, other	[3],[5]	9,044
Purchase price, total	[5]	$ 72,877
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]	291
Coulter Avenue 125 [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 1,925
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 1,925
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	6
Conroe Marketplace [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1],[5]	$ 18,546
Purchase price, debt assumed	[5]	42,350
Purchase price, other	[3],[5]	3,104
Purchase price, total	[5]	$ 64,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]	289
Laurel Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 1,200
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 1,200
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	4
District Heights [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1],[5]	$ 13,140
Purchase price, debt assumed	[5]	13,255
Purchase price, other	[3],[5]	950
Purchase price, total	[5]	$ 27,345
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]	91
Village on the Park [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 824
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 824
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	10
Christown Mall [Member[
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 51,351
Purchase price, debt assumed		63,899
Purchase price, other	[3]	0
Purchase price, total		$ 115,250
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	833
Washington St Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[1]	$ 8,750
Purchase price, debt assumed		0
Purchase price, other	[3]	0
Purchase price, total		$ 8,750
Purchase price, gross leasable area (in Square Feet) | ft²	[4]	0
North Valley [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 3,000
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 3,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			0
LaSalle Properties [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 62,239
Purchase price, debt assumed	[5]			23,269
Purchase price, other	[3],[5]			7,642
Purchase price, total	[5]			$ 93,150
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			316
Harrisburg Land Parcel [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 2,550
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 2,550
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			0
Crossroads Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 18,691
Purchase price, debt assumed				72,309
Purchase price, other	[3]			0
Purchase price, total				$ 91,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			489
Quail Corners [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 9,398
Purchase price, debt assumed	[5]			17,409
Purchase price, other	[3],[5]			4,943
Purchase price, total	[5]			$ 31,750
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			110
KIF 1 Portfolio [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 128,699
Purchase price, debt assumed	[5]			157,010
Purchase price, other	[3],[5]			122,291
Purchase price, total	[5]			$ 408,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			1,589
Fountains at Arbor Lakes [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 900
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 900
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			0
Boston Portfolio [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 149,486
Purchase price, debt assumed				120,514
Purchase price, other	[3]			0
Purchase price, total				$ 270,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			1,426
Vinnin Square [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 2,550
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 2,550
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			6
SEB Portfolio [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 69,261
Purchase price, debt assumed	[5]			193,600
Purchase price, other	[3],[5]			12,911
Purchase price, total	[5]			$ 275,772
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			1,415
Highlands Ranch Parcel [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 3,800
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 3,800
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			10
BIG Portfolios [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 0
Purchase price, debt assumed	[5]			118,439
Purchase price, other	[3],[5]			76,511
Purchase price, total	[5]			$ 194,950
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			1,148
Springfield S.C. [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 8,800
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 8,800
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			210
North Quincy Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 20,470
Purchase price, debt assumed	[5]			0
Purchase price, other	[3],[5]			2,530
Purchase price, total	[5]			$ 23,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			81
Belmart Plaza [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2],[5]			$ 3,208
Purchase price, debt assumed	[5]			0
Purchase price, other	[3],[5]			2,807
Purchase price, total	[5]			$ 6,015
Purchase price, gross leasable area (in Square Feet) | ft²	[4],[5]			77
Braelinn Village [Member]
Business Acquisition [Line Items]
Purchase price, cash	[2]			$ 27,000
Purchase price, debt assumed				0
Purchase price, other	[3]			0
Purchase price, total				$ 27,000
Purchase price, gross leasable area (in Square Feet) | ft²	[4]			227

[1] The Company utilized $89.5 million associated with Internal Revenue Code 1031 sales proceeds.

[2] Includes 1031 sales proceeds of $126.8 million

[3] Includes the Company's previously held equity interest investment.

[4] Gross leasable area ("GLA")

[5] The Company acquired from its partners the remaining ownership interest in these properties that were held in joint ventures in which the Company had a noncontrolling interest. The Company evaluated these transactions pursuant to the FASB's Consolidation guidance and as a result, recognized a gain on change in control of interest, net resulting from the fair value adjustment associated with the Company's previously held equity interest, which is included in the purchase price above in Other. The Company's previous ownership interest and gain on change in control of interests, net recognized as a result of these transactions are as follows: