|
Real Estate and Accumulated Depreciation - Additional Information (Detail) (USD $)
In Billions, unless otherwise specified |
Dec. 31, 2013
|
Dec. 31, 2012
|
|---|---|---|
| SEC Schedule III, Real Estate and Accumulated Depreciation Disclosure [Abstract] | ||
| Real estate investments for federal income tax | $ 1.1 | $ 1.1 |