Long-term Equity-based Compensation Plans Schedule of Nonvested Restricted Stock Units Activity (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended	9 Months Ended								0 Months Ended	36 Months Ended
	May 02, 2013	Sep. 30, 2013	Sep. 30, 2013 Time Vested Restricted Stock [Member]	Sep. 30, 2013 Performance Based Restricted Stock [Member]	Sep. 30, 2013 Restricted Stock [Member]	Sep. 30, 2012 Restricted Stock [Member]	Sep. 30, 2013 Performance Period, 2013 to 2015 [Member] Performance Based Restricted Stock [Member]	Sep. 30, 2013 Performance Period, 2012 to 2014 [Member] Performance Based Restricted Stock [Member]	Sep. 30, 2013 Performance Period, 2011 to 2013 [Member] Performance Based Restricted Stock [Member]	Feb. 02, 2013 Performance Period, 2010 to 2012 [Member] Performance Based Restricted Stock [Member]	Dec. 31, 2012 Performance Period, 2010 to 2012 [Member] Performance Based Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock, Nonvested at Beginning of Year, Number			126,349	187,075
Restricted Stock, Nonvested at Beginning of Year, Weighted Average Grant Date Fair Value			$ 26.19	$ 36.70
Restricted Stock, Grants in Period			71,625	70,675
Restricted Stock, Weighted Average Grant Date Fair Value			$ 29.95	$ 42.12
Restricted Stock, Vested in Period			(57,990)	(53,118)
Restricted Stock, Vested in Period, Weighted Average Grant Date Fair Value			$ 25.03	$ 33.14
Restricted Stock, Forfeited in Period			(31,694)	(24,632)
Restricted Stock, Forfeitures, Weighted Average Grant Date Fair Value			$ 26.88	$ 38.95
Restricted Stock, Nonvested at End of Period, Number			108,290	180,000
Restricted Stock, Nonvested at End of Period, Weighted Average Grant Date Fair Value			$ 29.10	$ 39.57
Number of Additional Shares To Be Granted If Maximum Perfornance Level Is Met or Exceeded							62,600	60,025	57,375
Payout Percentage for Exceeding Performance Target											114.00%
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures										6,996
Restricted Stock, Vested in Period, Total Fair Value					$ 4.0	$ 4.0
Restricted Stock, Vested in Period, Tax Benefits					$ 1.4	$ 1.4
Share-based Compensation, Initial Grant For Non Employee Director, Options		4,000
Share Based Compensation Arrangement By Share Based Payment Award, Automatic Annual Grant, Non-Employee Directors, Options		4,000
Performance Period				3 years
Annual Awards of Deferred Stock Units to be Issued to each Non-Employee Director	500
Deferred Stock Units Issued	4,000
Fair Value per Deferred Stock Unit Issued	$ 31.50