Financial Instruments, Derivatives and Hedging Activities (Details 4) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Fair value of assets and liabilities
Long -term debt, fair value	$ 1,860
Fair Value Measurements Recurring [Member] | Estimate Of Fair Value Fair Value Disclosure [Member]
Fair value of assets and liabilities
Available for sale securities	4	4
Derivatives assets	16	20
Derivatives liabilities	29	32
Long -term debt, fair value	1,855	1,813
Fair Value Measurements Recurring [Member] | Fair Value Inputs Level1 [Member]
Fair value of assets and liabilities
Available for sale securities	4	4
Derivatives assets	2
Derivatives liabilities	25	22
Fair Value Measurements Recurring [Member] | Fair Value Inputs Level2 [Member]
Fair value of assets and liabilities
Derivatives assets	14	20
Derivatives liabilities	4	10
Long -term debt, fair value	$ 1,855	$ 1,813