Lines of Credit and Financing Arrangements (Details Textual 3) (Senior Notes [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	May 31, 2010
Senior Notes [Member]
Debt Instrument [Line Items]
Senior unsecured notes	$ 200.0	$ 200.0	$ 200.0
Fixed interest rate for senior unsecured notes	4.90%
Maturity date of senior unsecured notes	May 15, 2017
Default long term debt description of violation or event of default of revolving credit facility	The indenture governing the notes contains covenants that, among other things, limit our ability and the ability of the subsidiary guarantors to: create or incur certain liens; enter into certain sale and leaseback transactions; enter into certain mergers, consolidations and transfers of substantially all of our assets; and transfer certain properties. The indenture also contains a cross default provision which is triggered if we default on other debt of at least $75 million in principal which is then accelerated, and such acceleration is not rescinded within 30 days of the notice date
Minimum principal amount accelerated	$ 75
Notice Date	30 days