Consolidated Balance Sheets (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares issued	48,683,493us-gaap_CommonStockSharesIssued	49,598,653us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	48,683,493us-gaap_CommonStockSharesOutstanding	49,598,653us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	10,126,473us-gaap_TreasuryStockShares	9,211,857us-gaap_TreasuryStockShares
Allowance for Doubtful Accounts [Member]
Allowances for receivables	$ 32.0	$ 39.2

Face amount or stated value per share of common stock.

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