Financing Arrangements (Senior Notes) (Details) (USD $)	9 Months Ended		9 Months Ended	12 Months Ended	9 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2013 6.375% Senior Notes [Member]	Dec. 31, 2007 6.375% Senior Notes [Member]	Sep. 30, 2013 Change in Control and Below Investment Grade Rating [Member] 6.375% Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, aggregate principal amount				$ 400,000,000
Debt instrument, stated interest rate (as a percentage)				6.375%
Debt instrument, maturity date				Jun. 01, 2017
Debt Instrument, Redemption Price (as a percentage)			100.00%		101.00%
Default on senior notes			0
Number of days in year per debt terms			360 days
Number of months in year per debt terms			12 months
Number of days in month, per debt terms			30 days
Debt instrument, benchmark for variable rate basis			Treasury rate
Treasury rate basis points (as a percentage)			0.30%
Senior note, failure to perform covenant	60 days
Senior note, grace period for defaulted payment	30 days
Threshold for noncompliance			50,000,000
Accelerated principal amount threshold			50,000,000
Senior notes amount	$ 399,248,000	$ 399,095,000