Losses associated with the earthquake in Japan (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended	16 Months Ended	6 Months Ended	16 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Earthquake in Japan, March 11, 2011 [Member]	Jun. 30, 2011 Earthquake in Japan, March 11, 2011 [Member]	Jun. 30, 2012 Earthquake in Japan, March 11, 2011 [Member]	Jun. 30, 2012 Insurance Settlement, Property Damage Claims [Member] Earthquake in Japan, March 11, 2011 [Member]	Jun. 30, 2012 Insurance Settlement, Business Interruption Claims [Member] Earthquake in Japan, March 11, 2011 [Member]	Jun. 30, 2012 Insurance Settlement, Business Interruption Claims [Member] Earthquake in Japan, March 11, 2011 [Member]
Operating income (loss)	$ 598	$ 905	$ 995	$ 1,813	$ 0	$ (80)	$ (101)	$ 25
Revenue	$ 3,335	$ 3,458	$ 6,456	$ 6,849					$ 75	$ 110

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 5

-Section 03

-Paragraph 1

Reference 2: 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)

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

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