|
Leased Facilities (Narrative) (Details) (USD $)
In Millions, unless otherwise specified |
12 Months Ended |
|---|---|
|
Dec. 31, 2011
|
|
| Leased Facilities [Abstract] | |
| Minimum undiscounted lease commitments | $ 7,914 |
| Estimated related rental income from noncancelable subleases | $ 107 |