Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Summarized Financial Information for RioCan - Income Statements (RioCan [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
RioCan [Member]
Schedule of Equity Method Investments [Line Items]
Revenues from rental properties	$ 202.5	$ 209.9	$ 213.3
Operating expenses	(74.6)	(76.9)	(78.1)
Interest expense	(31.9)	(40.1)	(51.9)
Depreciation and amortization	(33.5)	(36.0)	(37.3)
Other (expense)/income, net	(1.3)	(1.8)	14.7
	(141.3)	(154.8)	(152.6)
Net income	$ 61.2	$ 55.1	$ 60.7