Fair Value of Financial Instrument (Details) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of plan assets		$ 630.7
Derivative assets	$ 6.5	4.8
Derivative liabilities	13.4	13.8
Long-term debt		297.4
Trading securities		6.6
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of plan assets		490.0
Derivative assets	0.0	0.0
Derivative liabilities	0.0	0.0
Long-term debt		0.0
Trading securities		0.0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of plan assets		0.0
Derivative assets	6.5	4.8
Derivative liabilities	13.4	13.8
Long-term debt		297.4
Trading securities		6.6
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of plan assets		24.1
Derivative assets	0.0	0.0
Derivative liabilities	$ 0.0	0.0
Long-term debt		0.0
Trading securities		$ 0.0

Fair value of assets that have been segregated and restricted to provide pension or postretirement benefits. Assets include, but are not limited to, stocks, bonds, other investments, earnings from investments, and contributions by the employer and employees.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

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