|
Disclosure Of Fair Value Of Financial Instruments (Details) (USD $)
In Billions, unless otherwise specified |
Mar. 31, 2013
|
Dec. 31, 2012
|
|---|---|---|
| Disclosure Of Fair Value Of Financial Instruments [Abstract] | ||
| Fair value of Company's long-term debt | $ 2.5 | $ 2.4 |
| Book value of Company's long-term debt | $ 2.3 | $ 2.2 |