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Stock Repurchase Program (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended			9 Months Ended	35 Months Ended	1 Months Ended				35 Months Ended
	Jan. 31, 2013	Aug. 31, 2012	Aug. 31, 2011	Jun. 30, 2014	Jun. 30, 2014	Jan. 31, 2013 Maximum	Aug. 31, 2012 Maximum	Aug. 31, 2011 Maximum	Sep. 30, 2011 Accelerated Share Repurchase	Jun. 30, 2014 Rule 10b5-1 Repurchase Plan and Open Market Purchases
Stock Repurchase Program
Stock repurchase additional authorized amount	$ 500.0	$ 300.0	$ 200.0
Number of shares authorized to be repurchased									4.8
Authorized amount of stock repurchase						1,000.0	500.0	200.0	100.0
Shares repurchased and retired under the agreement					27.4					22.6
Total cost of shares repurchased under the agreement					660.1					560.1
Remaining repurchase amount of shares pursuant to the plan				$ 339.9
Average price per share of stock repurchased under the agreement (in dollars per share)					$ 24.10					$ 24.75

X

- Definition

The additional amount authorized by an entity's Board of Directors under a stock repurchase plan during the year.

+ References

No definition available.

+ Details

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- Definition

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

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3



Reference 2: 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 3: 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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- Definition

Equity impact of the value of stock that has been repurchased and retired during the period. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3



Reference 2: 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 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 29, 30, 31

-Article 5

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- Definition

Amount of a stock repurchase plan authorized by an entity's Board of Directors.

+ References

No definition available.

+ Details

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- Definition

The number of shares authorized to be repurchased by an entity's Board of Directors under a stock repurchase plan.

+ References

No definition available.

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- Definition

Amount remaining of a stock repurchase plan authorized by an entity's Board of Directors.

+ References

No definition available.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

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