v2.4.0.6
Organization (Details) (USD $)
3 Months Ended 60 Months Ended 3 Months Ended
Mar. 31, 2013
Y
acre
sqft
Vehicles
Investors
Mar. 31, 2013
acre
sqft
Vehicles
Investors
Mar. 31, 2012
Mar. 31, 2013
Commercial Real Estate Properties [Member]
sqft
Real_Estate_Properties
Mar. 31, 2013
Total Properties Under Construction [ Member]
Real_Estate_Properties
sqft
Mar. 31, 2013
Total Office Properties [ Member]
Real_Estate_Properties
Mar. 31, 2013
Class A Office Properties [Member]
Real_Estate_Properties
Mar. 31, 2013
Office Properties Under Construction [ Member]
Real_Estate_Properties
Mar. 31, 2013
Office Technical Properties [Member]
Real_Estate_Properties
Mar. 31, 2013
Hotel Property [ Member]
Real_Estate_Properties
Mar. 31, 2013
Retail Properties [ Member]
Real_Estate_Properties
Mar. 31, 2013
Residential Properties [Member]
Real_Estate_Properties
Mar. 31, 2013
Residential Properties Under Construction [Member]
Real_Estate_Properties
Mar. 31, 2013
Investments Through Value-Added Fund [Member]
Buildings
Mar. 26, 2018
Series B Cumulative Redeemable Preferred Stock [Member]
Mar. 31, 2013
Series B Cumulative Redeemable Preferred Stock [Member]
Dec. 31, 2012
Series B Cumulative Redeemable Preferred Stock [Member]
Mar. 31, 2013
Series Two Preferred Units [Member]
Mar. 31, 2013
series four preferred units [Member]
Mar. 31, 2013
Series B Preferred Units [Member]
Real Estate Properties [Line Items]                                        
General and limited partnership interest in the operating partnership (percent)   89.00% 88.40%                                  
Restriction on redemption of OP units from date of issuance (years) 1                                      
One OP unit is equivalent to one share of Common Stock (in shares) 1 1                                    
OP unit conversion rate (in shares) 1 1                                    
Series B, Shares Outstanding                               80,000 0     80,000
Series B, Dividend Rate, Percentage                             5.25%          
Number Of Series Of Preferred Units Outstanding 3 3                                    
OP Units for each Preferred Unit (in shares)                                   1.312336    
Preferred Units Liquidation Preference                                   $ 50.00 $ 50.00  
Quarterly Distributions to Series Four Preferred Units                                     $ 0.25  
Series Four Preferred Units Annual Dividend Payable Rate                                     2.00%  
Number of real estate properties       157 7 149 132 6 17 1 4 3 1 23            
Net Rentable Area       44,600,000 2,500,000                              
Number of vehicles in structured parking 46,939 46,939                                    
Area of parking (in square feet) 15,900,000 15,900,000                                    
Area of undeveloped land parcels owned (in acres) 513.8 513.8                                    
Value-added fund institutional investors (number of investors) 2 2                                    
Office Complexes                           2