Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

Name:	us-gaap_FairValueInputsDiscountRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Fair Value Disclosure (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2013 Carrying Amount Input Level 2, Fair Value	Dec. 31, 2012 Carrying Amount Input Level 2, Fair Value	Dec. 31, 2013 Fair Value Input Level 2, Fair Value	Dec. 31, 2012 Fair Value Input Level 2, Fair Value
Liabilities
Liabilities-Long-term debt excluding capital lease obligations				$ 7,486	$ 7,513	$ 7,226	$ 8,019
Fair value related additional information
Discount rates used in valuations (as a percent)	6.00%	7.50%	9.50%