Share Repurchase Program (Details Textuals) (USD $) Share data in Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Share Repurchase Program Summary
Share Repurchase Program, Authorized Amount	$ 1,250,000,000
Share Repurchase Program, Remaining Authorized Repurchase Amount	646,100,000
Share Repurchased and Retired During Program, Shares	12.56
Payments for Repurchase of Common Stock, Aggregate	603,900,000
Share Repurchased and Retired During Period, Shares	6.83
Payments for Repurchase of Common Stock During Period	$ 369,900,000

Number of shares that have been repurchased and retired during the period.

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30

-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration