Debt - Interest Expense and Related Borrowings (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 9 Months Ended
Sep. 30, 2014
Sep. 30, 2013
Sep. 30, 2014
Sep. 30, 2013
Schedule Of Interest Expenses [Line Items]        
Amortization of deferred financing costs $ 1,787 $ 2,327 $ 4,084 $ 12,457
Amortization of debt (premium)/discount     (821) 5,588
Total interest expense 53,535 50,386 163,926 126,376
Revolving Credit Facilities
       
Schedule Of Interest Expenses [Line Items]        
Interest expense 538 1,196 2,358 1,572
Mortgages and Notes Payable
       
Schedule Of Interest Expenses [Line Items]        
Interest expense 44,858 47,196 149,231 106,284
Convertible notes
       
Schedule Of Interest Expenses [Line Items]        
Interest expense 6,098 0 8,970 0
Other Interest Expense
       
Schedule Of Interest Expenses [Line Items]        
Interest expense 32 8 104 475
Interest Expense
       
Schedule Of Interest Expenses [Line Items]        
Amortization of debt (premium)/discount $ 222 $ (341) $ (821) $ 5,588