Consolidated Statements of Income (Parenthetical) (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Income [Abstract]
Interest income	$ 0	$ 1
Tax (benefit) expense on gain (loss) on dispositions from discontinued operations	$ 1	$ 1

Interest generated from day to day operating activities of the business. This element represents a revenue generating activity and is therefore gross (before any related cost of revenue items).

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

Name:	us-gaap_InterestIncomeOperating
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration