Debt (Schedule Of Weighted Average Commercial Paper Balances And Weighted Average Interest Rates) (Details) (Commercial Paper [Member], USD $) In Millions, unless otherwise specified	1 Months Ended
Dec. 31, 2012	Nov. 30, 2012	Oct. 31, 2012	Sep. 30, 2012	Aug. 31, 2012	Jul. 31, 2012	Jun. 30, 2012	May 31, 2012	Apr. 30, 2012	Mar. 31, 2012	Feb. 29, 2012	Jan. 31, 2012
Commercial Paper [Member]
Short-term Debt [Line Items]
Weighted Average Interest Rate	0.29%	0.28%	0.29%	0.34%	0.00%	0.00%	0.00%	0.35%	0.36%	0.38%	0.00%	0.27%
Average Balance	$ 11.9	$ 14.5	$ 9.3	$ 4.2	$ 0	$ 0	$ 0	$ 0.8	$ 6.3	$ 8.0	$ 0	$ 62.7

Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of short-term debt outstanding by type or by instrument at that time.

Reference 1: 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))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Subparagraph b

-Article 5

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant