Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Income Taxes [Abstract]
Effective tax rate	37.30%	37.50%	37.70%	37.90%
Percentage of tax position benefit maximum than being realized upon ultimate settlement			50.00%
Uncertain tax positions liabilities	$ 0.1		$ 0.1
Unrecognized tax positions that, if recognized, would affect the effective tax rate	$ 0.1		$ 0.1