Investments (Maturities Of Securities Excluding Trading Securities) (Details) (USD $) In Millions, unless otherwise specified	Feb. 12, 2012
Investments [Abstract]
Available-For-Sale, Cost Basis due in one year or less	$ 956
Available-For-Sale, Cost Basis due after one year through five years	318
Available-For-Sale, Cost Basis due after five years	6
Available-For-Sale, Cost Basis, total	1,280
Available-For-Sale, Fair Value due in one year or less	958
Available-For-Sale, Fair Value due after one year through five years	324
Available-For-Sale, Fair Value due after five years	6
Available-For-Sale, Fair Value, total	1,288
Held-To-Maturity, Cost Basis due in one year or less	108
Held-To-Maturity, Cost Basis due after one year through five years	0
Held-To-Maturity, Cost Basis due after five years	0
Held-To-Maturity, Cost Basis, total	108
Held-To-Maturity, Fair Value due in one year or less	108
Held-To-Maturity, Fair Value due after one year through five years	0
Held-To-Maturity, Fair Value due after five years	0
Held-To-Maturity, Fair Value, total	$ 108