Commitments and Contingencies Personal Injury Liability Activity (Details) - Personal Injury [Member] - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Personal Injury Liability Activity [Roll Forward]
Balance at beginning of year	$ 20.9	$ 19.6
Accruals	6.3	6.3
Changes in estimate	9.4	0.2
Payments	(5.3)	(5.2)
Balance at end of year	$ 31.3	$ 20.9

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

No definition available.

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- Definition

Amount of loss contingency liability.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

+ Details

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- Definition

Amount of cash outflow reducing loss contingency liability.

+ References

+ Details

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- Definition

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

+ References

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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- Details

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