Initiatives (Details) (USD $) In Millions, except Share data	0 Months Ended
Dec. 15, 2010	Jun. 30, 2011
Initiatives
ASR agreement with the bank to repurchase of common stock	$ 750
Number of shares received under ASR transaction	8,100,000
Shares subject to mandatory redemption settlement, shares		640,000

The number of shares that would be issued, determined under the conditions specified in the contract, if the settlement were to occur at the reporting date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 150
-Paragraph 27
-Subparagraph a
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 480
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6940734&loc=d3e22047-110879

Name:	us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsNumberOfShares
Namespace Prefix:	us-gaap
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant