Note 3 - Discontinued Operations (Details) (USD $)	6 Months Ended
	Jun. 30, 2013 sqft		Jun. 30, 2012	Dec. 31, 2012
Note 3 - Discontinued Operations (Details) [Line Items]
Number of Real Estate Properties	4
(in Square Feet)	2,287,000	[1]
Real Estate Held-for-sale	$ 21,400,000
Real Estate Investment Property, Accumulated Depreciation	1,835,280,000			1,745,462,000
Impairment of Real Estate	81,500,000		34,600,000
Fair Value Of Real Estate	39,506,000			52,505,000
Assets Held-for-sale [Member] | Remaining [Member]
Note 3 - Discontinued Operations (Details) [Line Items]
Real Estate Held-for-sale	38,100,000
Real Estate Investment Property, Accumulated Depreciation	5,400,000
Assets Held-for-sale [Member] | Operating Properties [Member]
Note 3 - Discontinued Operations (Details) [Line Items]
Number of Real Estate Properties	5
Assets Held-for-sale [Member] | Three Operating Properties [Member]
Note 3 - Discontinued Operations (Details) [Line Items]
Impairment of Real Estate	9,900,000
Fair Value Of Real Estate	27,600,000
Assets Held-for-sale [Member]
Note 3 - Discontinued Operations (Details) [Line Items]
(in Square Feet)	163,381
Real Estate Investment Property, Accumulated Depreciation	4,500,000
Sold [Member] | Operating Properties [Member]
Note 3 - Discontinued Operations (Details) [Line Items]
Number of Real Estate Properties				1
Operating Properties [Member]
Note 3 - Discontinued Operations (Details) [Line Items]
Impairment of Real Estate	$ 20,800,000

[1] Gross leasable area ("GLA")