Fair Value and Financial Instruments (Details 3) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt	$ 4,479	$ 4,014
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt	4,479	4,014
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Long-term debt	$ 4,700	$ 4,172

Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year (current maturities) or the normal operating cycle, if longer, and after deducting unamortized discount or premiums, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

Name:	us-gaap_LongTermDebtNoncurrent
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant