Condensed Consolidated Statements Of Financial Position (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Trade accounts receivable, allowances	$ 49.1	$ 39.0
Property and equipment, accumulated depreciation	$ 1,135.6	$ 1,079.1
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	606,200,000	609,000,000
Class A common stock, shares outstanding	606,200,000	609,000,000