Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
KimPru and KimPru II [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 777.1	$ 920.0
Average Interest Rate		5.54%	5.53%
Average Remaining Term	[1]	12 months 18 days	23 months
KIR [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 811.6	$ 860.7
Average Interest Rate		4.64%	5.04%
Average Remaining Term	[1]	62 months 9 days	61 months 27 days
Kimstone [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 0.0	$ 701.3
Average Interest Rate		0.00%	4.45%
Average Remaining Term	[1]	0 years	28 months 21 days
BIG Shopping Centers [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 54.5	$ 144.6
Average Interest Rate		5.45%	5.52%
Average Remaining Term	[1]	10 months 3 days	22 months
CPP [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 109.9	$ 112.0
Average Interest Rate		5.25%	5.05%
Average Remaining Term	[1]	3 months 15 days	10 months 3 days
Other Institutional Programs [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 163.9	$ 272.9
Average Interest Rate		4.74%	5.21%
Average Remaining Term	[1]	24 months	23 months 15 days
RioCan [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 87.5	$ 640.5
Average Interest Rate		5.02%	4.29%
Average Remaining Term	[1]	11 months	39 months 27 days
Other Joint Venture Programs [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 794.6	$ 921.9
Average Interest Rate		5.26%	5.31%
Average Remaining Term	[1]	47 months 18 days	58 months 18 days
All Equity Method Investments [Member]
Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Joint Venture Investments Accounted for under the Equity Method - Debt Details [Line Items]
Mortgages and Notes Payable		$ 2,799.1	$ 4,573.9

[1] Average remaining term includes extensions