Condensed Consolidated Statements Of Financial Position (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances	$ 33.3	$ 36.9
Property and equipment, accumulated depreciation	$ 957.8	$ 852.1
Preferred stock, par value (in dollars per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized	15,000,000	15,000,000
Preferred stock, issued	0	0
Class A common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Class A common stock, shares authorized	1,000,000,000	1,000,000,000
Class A common stock, shares issued	609,500,000	609,400,000
Class A common stock, shares outstanding	609,500,000	609,400,000