Acquisitions (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2009	Dec. 31, 2011	Dec. 31, 2010
Acquisitions (Textual) [Abstract]
Annual sale after acquisition	$ 11
Outstanding contingent consideration		0	0
Total net cash purchase price of acquisitions	$ 6	$ 10

Fair value, as of the acquisition date, of potential payments under the contingent consideration arrangement including cash and shares.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph g(1)

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141

-Paragraph 51

-Subparagraph f

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 29, 30, 41, 42, 64

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 65

-Subparagraph a, b

Name:	us-gaap_BusinessAcquisitionContingentConsiderationAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant