Commitments and Contingencies (Details Textuals) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Class of Stock [Line Items]
Discount To Liquidation Preference for Repurchase of Portion of CRA Preferred Stock Value	$ 10,000,000	$ 10,000,000
Temporary Equity, Carrying Amount	10,000,000	10,000,000	20,000,000
Commitments and Contingencies (Textuals) [Abstract]
Commitments related to capital spending activities		14,000,000
Term of commitments to purchase goods or services related to the operations of properties		one year or less
Commitment to advance funds	3,400,000	3,400,000
Maximum cash payment required for acquisition of certain properties that collateralize our notes receivable upon the obligor's exercise of put option	30,700,000	30,700,000
Assumption of property debt required for acquisition of certain properties that collateralize our notes receivable upon the obligor's exercise of put option	118,500,000	118,500,000
Amount of additional consideration accrued for purchase of noncontrolling interests in consolidated real estate partnerships	7,500,000	7,500,000
Range of remaining compliance periods for tax credit syndication arrangements		less than one year to 15 years
Series A CRA Preferred Stock [Member]
Class of Stock [Line Items]
Discount to liquidation preference for repurchase of a portion of CRA Preferred Stock	30.00%	30.00%
Temporary Equity, Carrying Amount	$ 10,000,000	$ 10,000,000