Income Taxes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Effective tax rate	4.40%	15.20%	6.50%	10.00%
Tax benefit from reduction of liability for uncertain tax positions			$ 0.2
Unrecognized tax benefits	$ 1.1		$ 1.1		$ 1.2