Annual report pursuant to Section 13 and 15(d)

Debt (Details)

v2.4.0.6
Debt (Details) (USD $)
 12 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended 4 Months Ended 5 Months Ended 12 Months Ended 5 Months Ended 1 Months Ended 4 Months Ended 12 Months Ended 5 Months Ended 11 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Dec. 31, 2012
Fixed rate mortgage loans
Dec. 31, 2011
Fixed rate mortgage loans
Dec. 31, 2012
Revolving Construction Facility
Dec. 31, 2011
Revolving Construction Facility
Sep. 30, 2011
Variable rate secured loans
Loan
Dec. 31, 2012
Variable rate secured loans
Dec. 31, 2011
Variable rate secured loans
Dec. 31, 2012
Other construction loan facilities
Dec. 31, 2011
Revolving Credit Facility
Dec. 31, 2012
Revolving Credit Facility
Dec. 31, 2012
Revolving Credit Facility
Aug. 10, 2012
Revolving Credit Facility
Sep. 01, 2011
Revolving Credit Facility
Dec. 31, 2012
Revolving Credit Facility
Maximum
Dec. 31, 2012
Revolving Credit Facility
Minimum
Dec. 31, 2012
Revolving Credit Facility
LIBOR 30-day
Aug. 31, 2012
Term Loan Facility
Feb. 29, 2012
Term Loan Facility
Sep. 30, 2011
Term Loan Facility
Dec. 31, 2011
Term Loan Facility
Dec. 31, 2012
Term Loan Facility
Aug. 03, 2012
Term Loan Facility
Dec. 31, 2012
Term Loan Facility
LIBOR 30-day
Dec. 31, 2012
Term Loan Facility
LIBOR 30-day
Dec. 31, 2012
Term Loan Facility
LIBOR 30-day
Aug. 03, 2012
Term Loan Facility
LIBOR 30-day
Feb. 14, 2012
Term Loan Facility
LIBOR 30-day
Sep. 01, 2011
Term Loan Facility
LIBOR 30-day
Apr. 30, 2010
4.25% Exchangeable Senior Notes
Dec. 31, 2012
4.25% Exchangeable Senior Notes
Dec. 31, 2011
4.25% Exchangeable Senior Notes
Dec. 31, 2010
4.25% Exchangeable Senior Notes
Dec. 31, 2012
Unsecured notes payable
Dec. 31, 2011
Unsecured notes payable
Sep. 30, 2011
3.5% Exchangeable Senior Notes
Dec. 31, 2011
3.5% Exchangeable Senior Notes
Dec. 31, 2010
3.5% Exchangeable Senior Notes
Sep. 15, 2011
3.5% Exchangeable Senior Notes
Debt                                                                                  
Maximum Availability                     $ 123,802,000   $ 800,000,000 $ 800,000,000 $ 800,000,000                 $ 770,000,000                                  
Stated interest rate (as a percent)                                                                 4.25%     0.00% [1]         3.50%
Description of variable rate basis                 LIBOR [2]   LIBOR [3]     LIBOR [4]         LIBOR         LIBOR [5]   LIBOR LIBOR LIBOR                          
Variable rate, spread (as a percent)                 2.25% [2]                                                                
Stated Interest Rates, low end of range (as a percent)       5.20% [6],[7]                                                                          
Stated Interest Rates, high end of range (as a percent)       7.87% [6],[7]                                                                          
Variable rate, spread low end of range (as a percent)                     1.95% [3]   1.75% [4] 1.75% [4]         1.75%         1.65% [5]         2.10% 1.65% 1.65%                    
Variable rate, spread high end of range (as a percent)                     2.75% [3]   2.50% [4] 2.50% [4]         2.50%         2.60% [5]         2.60% 2.40% 2.40%                    
Unamortized premium included in carrying value       1,300,000 2,400,000                                                                        
Weighted average interest rate (as a percent)       6.01%             2.66%                         2.17%                                  
Line of credit, maximum availability before reduction                               1,000,000,000                                                  
Interest rate on debt (as a percent)                 2.46%                                                                
Expansion right, maximum borrowing capacity                             1,300,000,000 1,500,000,000                                                  
Amount available as a percentage of unencumbered Asset value                         60.00%                                                        
Extension option period (in years)                       1 year                   1 year                                      
Extension fee as a percentage of total availability of the facility                         0.20%                   0.20%                                    
Percentage of quarterly fee                                 0.35% 0.25%                                              
Remaining borrowing capacity                         792,300,000 792,300,000                                                      
Number of loans repaid upon entry into Revolving Credit Facility and Term Loan Agreement               2                                                                  
Initial amount borrowed                                       120,000,000 250,000,000 400,000,000                   240,000,000                  
Additional borrowing capacity available provided there is no default under the agreement                                             100,000,000   80,000,000                                
Amount of loans repaid upon entry into Revolving Credit Facility and Term Loan Agreement               270,300,000                                                                  
Loss on early extinguishment of debt 943,000 1,639,000 0             1,700,000                                                              
Unamortized discount included in carrying value                                                                 9,100,000 12,700,000   873,000 1,800,000        
Exchange rate per $1000 principal amount (in common shares)                                                                 20.8513                
Convertible debt principal amount, basis for exchange                                                                 1,000                
Exchange price per common share based on exchange rate (in dollars per share)                                                                 $ 47.96                
Percentage over the entity's common stock price at the time of issuance which was used to determine the initial exchange rate                                                                     20.00%            
Principal amount of debt 2,027,792,000 [8]                                                               240,000,000               162,500,000
Effective interest rate, including amortization of issuance costs (as a percent)                                                                 6.05%               5.97%
Interest expense at stated interest rate                                                                 10,200,000 10,200,000 7,480,000       4,013,000 5,687,000  
Interest expense associated with amortization of discount 3,155,000 5,540,000 5,841,000                                                           3,651,000 3,437,000 2,445,000       2,617,000 3,736,000  
Total interest expenses                                                                 13,851,000 13,637,000 9,925,000       6,630,000 9,423,000  
Weighted average borrowings           276,500,000 482,300,000                                                                    
Weighted average interest rate (as a percent)           2.27% 1.65%                                                                    
Capitalized interest costs 13,900,000 17,400,000 16,500,000                                                                            
Repurchase of notes, percentage of principal paid                                                                 100.00%               100.00%
Debt Instrument, Decrease, Repayments                                                                           $ 162,500,000      
[1] These notes carry interest rates that were below market rates upon assumption and therefore were recorded at their fair value based on applicable effective interest rates. The carrying value of these notes reflects an unamortized discount totaling $873,000 at December 31, 2012 and $1.8 million at December 31, 2011.
[2] The interest rate on the loan outstanding was 2.46% at December 31, 2012.
[3] The weighted average interest rate on these loans was 2.66% at December 31, 2012.
[4]
[5] The weighted average interest rate on these loans was 2.17% at December 31, 2012.
[6] The weighted average interest rate on these loans was 6.01% at December 31, 2012.
[7] Several of the fixed rate mortgages carry interest rates that were above or below market rates upon assumption and therefore were recorded at their fair value based on applicable effective interest rates. The carrying values of these loans reflect net unamortized premiums totaling $1.3 million at December 31, 2012 and $2.4 million at December 31, 2011.
[8] Represents scheduled principal amortization and maturities only and therefore excludes net discounts of $8.6 million.