Fair Value Disclosure (Tables)

6 Months Ended

Jun. 30, 2013

Fair Value Disclosure

Schedule of the three input levels in the hierarchy of fair value measurements

Input Level	Description of Input
Level 1	Observable inputs such as quoted market prices in active markets.
Level 2	Inputs other than quoted prices in active markets that are either directly or indirectly observable.
Level 3	Unobservable inputs in which little or no market data exists.

Schedule of carrying amounts and estimated fair values of long-term debt, excluding capital lease obligations, and input level to determine fair values

			June 30, 2013				December 31, 2012
	Input Level		Carrying Amount		Fair Value		Carrying Amount		Fair Value
	(Dollars in millions)
Liabilities—Long-term debt, excluding capital lease obligations		2	$	19,902		20,680		19,871		21,457