Subsequent Events (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	1 Months Ended
Sep. 30, 2012 Pre Twenty Eleven Restricted Stock Units	Oct. 24, 2012 Subsequent Event Unsecured Term Loan	Sep. 30, 2012 October and November Twenty Twelve Pre Twenty Eleven Restricted Stock Units
Subsequent Event
Line of credit facility, maximum borrowing capacity		$ 1,500
Interest payable on borrowed amounts		1.00%
Letter of credit facility upfront fee percentage		0.15%
Commitment fee payable per annum on daily undrawn balance		0.10%
Number of Borrowings Under Term Loan		2
Share based compensation arrangement by share based payment award other than options expected to vest			271
Withholding tax rate	45.00%

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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