|
Noncontrolling Interests (Property Partnerships) (Narrative) (Details) (USD $)
|
6 Months Ended | 0 Months Ended | |||||
|---|---|---|---|---|---|---|---|
|
Jun. 30, 2013
|
Jun. 30, 2012
|
Dec. 31, 2012
|
Mar. 26, 2013
Transbay Tower [Member]
floor
sqft
|
Feb. 26, 2013
Transbay Tower [Member]
|
Feb. 07, 2013
Transbay Tower [Member]
|
May 31, 2013
767 Fifth Avenue (The GM Building) [Member]
partners
sqft
|
|
| Noncontrolling Interest [Line Items] | |||||||
| Property partnerships | $ 489,389,000 | $ (1,964,000) | |||||
| Partners Joint Venture Ownership Percentage | 5.00% | 50.00% | |||||
| Ownership Percentage | 95.00% | 95.00% | 40.00% | ||||
| Number of floors real estate | 60 | ||||||
| Net Rentable Area | 1,400,000 | 1,800,000 | |||||
| Payments to Acquire Land | 192,000,000 | ||||||
| Number of Joint Venture Partners | 2 | ||||||
| Noncontrolling interest recorded upon consolidation | $ 483,488,000 | $ 0 | $ 483,488,000 | ||||