Commitments and Contingencies Personal Injury Liability Activity (Details) (Personal Injury [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
Personal Injury [Member]
Personal Injury Liability Activity [Roll Forward]
Balance at beginning of year	$ 31.2	$ 34.4
Accruals	8.8	8.8
Change in estimate	(4.2)	1.3
Payments	(6.5)	(13.3)
Balance at end of year	$ 29.3	$ 31.2

Amount of increase decrease in loss contingency liability for change in estimate

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- Definition

Amount of loss contingency liability.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 450

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14326-108349

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- Definition

Amount of payments made reducing loss contingency liability.

+ References

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- Definition

Amount charged against operating income increasing loss contingency liability, after adjustments to reduce previously estimated charges.

+ References

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