Fair Value Measurements And Disclosure (Fair Value Leveling) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	$ 176	$ 191
Liability Derivatives (at fair value)	(8)	(7)
Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	2,020	1,951
Liability Derivatives (at fair value)	(534)	(519)
Domestic Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	1,055	1,049
International Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	543	563
Fixed Income Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	947	759
Level 1 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	0	0
Liability Derivatives (at fair value)	0	0
Level 1 [Member] | Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	0	0
Liability Derivatives (at fair value)	0	0
Level 1 [Member] | Domestic Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	1,055	1,049
Level 1 [Member] | International Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	543	563
Level 1 [Member] | Fixed Income Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	0	0
Level 2 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	176	191
Liability Derivatives (at fair value)	(8)	(7)
Level 2 [Member] | Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	2,020	1,951
Liability Derivatives (at fair value)	(534)	(519)
Level 2 [Member] | Domestic Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	0	0
Level 2 [Member] | International Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	0	0
Level 2 [Member] | Fixed Income Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	947	759
Level 3 [Member] | Interest Rate Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	0	0
Liability Derivatives (at fair value)	0	0
Level 3 [Member] | Cross-Currency Swaps [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Asset Derivatives (at fair value)	0	0
Liability Derivatives (at fair value)	0	0
Level 3 [Member] | Domestic Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	0	0
Level 3 [Member] | International Equities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	0	0
Level 3 [Member] | Fixed Income Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-Sale Securities (at fair value)	$ 0	$ 0