Commitments and Contingencies (Details Textuals) (USD $)	9 Months Ended
	Sep. 30, 2011	Dec. 31, 2010
Class of Stock [Line Items]
Temporary Equity, Carrying Amount	$ 10,000,000	$ 20,000,000
Commitments and Contingencies (Textuals) [Abstract]
Commitments related to capital spending activities	19,300,000
Commitment to advance funds	3,200,000
Maximum cash payment required for acquisition of certain properties that collateralize our notes receivable upon the obligor's exercise of put option	31,200,000
Assumption of property debt required for acquisition of certain properties that collateralize our notes receivable upon the obligor's exercise of put option	118,000,000
Range of remaining compliance periods for tax credit syndication arrangements	less than one year to 15 years
Term of commitments to purchase goods or services related to the operations of properties	one year or less
Amount of additional consideration accrued for purchase of noncontrolling interests in consolidated real estate partnerships	7,500,000
CRA Preferred Stock [Member]
Class of Stock [Line Items]
Discount to liquidation preference for repurchase of a portion of CRA Preferred Stock	30.00%
Liquidation Preference of Preferred Stock Subject to Repurchase Agreement	10,000,000
Temporary Equity, Carrying Amount	$ 10,000,000