Provision for Impairment Losses As Follows (In Millions) (Details) (USD $)	12 Months Ended
	Dec. 31, 2012
Provision for impairment of notes receivable, invest and real estate assets	$ 4.7
prior year expense	44.4
Decrease compared to the prior year expense	39.7
Impairment reserve to a deficiency agreement	2.4
Impairment reserves related to land holdings	2.3
Texas land holding resulted in an impairment reserve	1.2
Florida land holding resulted in an impairment reserve	0.5
Arkansas land holding resulted in an impairment reserve	0.6
Prior period impairment recorded as an additional loss in the investment portfolio	5.2
Apartment properties currently hold	2.0
land parcels currently hold	2.4
land that was sold subsequent to the prior period	24.4
Impairment on investments in joint ventures	0.4
Reserve related to the assets held by American Realty Trust	10.0
Impairment reserves taken in the prior period	20.0
Seller financed note	10.0
Related To Third Party Sales	8.8
Related to the underperformance of property using a valuation analysis	5.2
Related to various investment in joint ventures	$ 0.4