Benefit Plans, Estimated Amortization of Amounts in Other Accumulated Comprehensive Income (Details) $ in Millions	Dec. 31, 2017 USD ($)
Pension Benefits [Member]
Amounts that will be amortized from Accumulated other comprehensive income (loss) in next fiscal year [Abstract]
Amortization of prior service credit (gain) loss	$ 0.0
Amortization of net (gain) loss	11.5
Total costs to be recognized	11.5
Post-retirement Benefits [Member]
Amounts that will be amortized from Accumulated other comprehensive income (loss) in next fiscal year [Abstract]
Amortization of prior service credit (gain) loss	(0.9)
Amortization of net (gain) loss	(0.6)
Total costs to be recognized	$ (1.5)

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- Definition

Amount of cost (credit) included in accumulated other comprehensive (income) loss expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (s)
-URI http://asc.fasb.org/extlink&oid=82843861&loc=d3e1928-114920

+ Details

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- Definition

Amount included in accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan expected to be recognized in net periodic benefit (cost) credit for fiscal year following most recent annual statement of financial position.

+ References

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- Definition

Amount included in accumulated other comprehensive (income) loss for prior service cost (credit) expected to be recognized in net periodic benefit cost (credit) for fiscal year following most recent annual statement of financial position.

+ References

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