Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Allowance for doubtful accounts	$ 15.0	$ 13.3
Accumulated depreciation	1,484.1	1,497.0
Debt payable within one year	$ 724.3	$ 23.1
Common stock issued, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock issued, shares authorized (in shares)	300,000,000	300,000,000
Common stock issued, shares outstanding (in shares)	66,188,600	66,735,913
Treasury stock, at cost (shares)	11,268,033	10,720,720
Senior Notes, Due 2021 [Member]
Debt Instrument [Line Items]
Debt payable within one year	$ 700.0

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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