Balance Sheet Parenthetical (Parentheticals) (USD $) In Millions, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets
Allowance for doubtful accounts	$ 5.8	$ 7.4
Stockholders' equity
Preferred Stock, par value	$ 0.01
Common Stock, par value	$ 0.01
Common Stock, shares authorized	800.0
Common Stock, shares outstanding	271.7	270.1
Treasury Stock, shares	14.0	13.8
Preferred Stock [Member]
Stockholders' equity
Preferred Stock, par value	$ 0.01	$ 0.01
Preferred Stock, shares authorized	10.0	10.0
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Perpetual Preferred Stock Member
Stockholders' equity
Preferred Stock, shares authorized	0.8	0.8
Preferred Stock, shares issued	0	0
Preferred Stock, shares outstanding	0	0
Series Common Stock Member
Stockholders' equity
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	40.0	40.0
Common Stock, shares issued	0	0
Common Stock, shares outstanding	0	0
Common Stock [Member]
Stockholders' equity
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	800.0	800.0
Common Stock, shares issued	285.7	283.9
Common Stock, shares outstanding	271.7	270.1