Fair Value Measurements (Details 2) (USD $)
In Thousands, unless otherwise specified |
Jun. 30, 2013
|
Dec. 31, 2012
|
---|---|---|
Fair Value Disclosures [Abstract] | ||
Carrying Value, Mortgage and notes payable | $ 5,274,583 | $ 5,894,443 |
Carrying Value, Margins payable | 22,097 | 139,142 |
Estimated Fair Value, Mortgage and notes payable | 5,317,999 | 5,790,201 |
Estimated Fair Value, Margins payable | $ 22,097 | $ 139,142 |