Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Investment and Advances to Real Estate Joint Ventures - Balance Sheets - Excluding KIR and RioCan [Member] - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Assets:
Assets	$ 5,107.7	$ 7,734.6
Liabilities and Partners’/Members’ Capital:
Noncontrolling interests	92.5	21.4
Partners’/Members’ capital	2,199.9	3,018.6
	5,107.7	7,734.6
Real Estate [Member]
Assets:
Assets	4,855.5	7,422.0
Other Assets [Member]
Assets:
Assets	252.2	312.6
Mortgage Payable [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities	2,770.1	4,553.1
Construction Loans [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities	29.0	21.0
Other Liabilities [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities	$ 16.2	$ 120.5