Note 7 - Investment and Advances in Real Estate Joint Ventures (Details) - Investment and Advances to Real Estate Joint Ventures - Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Assets:
Assets	$ 6,991.9	$ 9,031.0
Liabilities and Partners’/Members’ Capital:
Noncontrolling interests	19.2	19.1
Partners’/Members’ capital	2,914.5	3,593.8
	6,991.9	9,031.0
Real Estate [Member]
Assets:
Assets	6,601.8	8,523.3
Other Assets [Member]
Assets:
Assets	390.1	507.7
Notes Payable [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities		148.0
Mortgage Payable [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities	3,956.2	5,056.5
Construction Loans [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities		25.1
Other Liabilities [Member]
Liabilities and Partners’/Members’ Capital:
Liabilities	$ 102.0	$ 188.5