Note 10 - Variable Interest Entities (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Variable Interest Entity, Primary Beneficiary [Member] | Operating Properties [Member]
Number of Consolidated Entities	2
Variable Interest Entity, Consolidated, Carrying Amount, Assets	$ 10.8
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	0.1
Variable Interest Entity, Primary Beneficiary [Member] | Ground Up Developments [Member]
Number of Consolidated Entities	2
Variable Interest Entity, Consolidated, Carrying Amount, Assets	87.8
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities	0.1
Variable Interest Entity, Financial or Other Support, Amount	33.3
Variable Interest Entity, Not Primary Beneficiary [Member] | Ground Up Developments [Member]
Variable Interest Entity, Financial or Other Support, Amount	17.9
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	36.3
Variable Interest Entity, Financial or Other Support, Future Funding	18.4
Variable Interest Entity, Not Primary Beneficiary [Member] | Preferred Equity Investments [Member]
Number of Consolidated Entities	1
Variable Interest Entity, Not Primary Beneficiary [Member] | Redevelopment [Member]
Variable Interest Entity, Financial or Other Support, Amount	12.1
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount	$ 12.1