Summary Of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Dec. 31, 2011 years months	Jan. 31, 2011
Summary Of Significant Accounting Policies [Line Items]
Equity method investment, ownership percentage	100.00%	51.00%
Expected lease-up periods for estimating lost rentals, in months	6
Percentage of ordinary taxable income to be distributed for real estate investment trust qualification	90.00%
Number of years of federal income tax at corporate rates on failure to qualify as REIT	4
Stock award vesting period in years, minimum	three
Stock award vesting period in years, maximum	seven
Time-Based Awards [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock award vesting period in years, minimum	three
Stock award vesting period in years, maximum	seven
Market Conditions Based Awards [Member]
Summary Of Significant Accounting Policies [Line Items]
Stock award vesting period in years, minimum	three
Stock award vesting period in years, maximum	seven