Long-Term Debt (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014
Debt Instrument [Line Items]
Unsecured senior revolving credit facility	$ 300.0
Increase in the senior credit facility	150.0
Line of credit facility, remaining borrowing capacity	167.6
Letters of credit and bank guarantees outstanding, amount	6.2
Voluntary retirement payments guaranteed	4.1
Industrial Development Debt Payable Through 2022, 0.30%
Debt Instrument [Line Items]
Extinguishment of debt, amount	4.0
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	2.4
Unspecified Arrangement
Debt Instrument [Line Items]
Restricted cash and cash equivalents	2.3
Senior Notes
Debt Instrument [Line Items]
Debt instrument, potential face amount	$ 175.0