Consolidated Statement of Stockholders' Equity Stockholders Equity Parenthetical (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Statement of Stockholders' Equity [Abstract]
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized (Gain) Loss Arising During Period, Tax	$ 0.1	$ 1.4	$ 0.9
Other Comprehensive Income (Loss), Reclassification Adjustment on Derivatives Included in Net Income, Tax	$ 0.1	$ 0.2	$ 0.3