v2.4.0.6
Capital Stock (Details 3)
12 Months Ended
Dec. 31, 2011
Y
Excess Share Provision  
Percentage of beneficial ownership of common stock acquired used as threshold for determining excess shares 9.00%
Percentage of beneficial ownership of preferred stock acquired used as threshold for determining excess shares 9.90%
Maximum deferral payment period of purchase price for excess shares (in years) 5
Distribution Reinvestment and Stock Purchase Plan  
Discount on purchase price of common stock to shareholders reinvesting their dividends and/or make optional cash purchases through the DRIP (as a percent) 1.00%