Stockholders' Equity Dividends Paid (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Dec. 31, 2012	Sep. 30, 2010	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stockholders' Equity Attributable to Parent [Abstract]
Payments of Dividends	$ 85.0	$ 90.7	$ 6.9	$ 7.1	$ 7.3