Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Trade accounts receivable allowance	$ 103.7	$ 102.5
Common stock par value	$ 0.01	$ 0.01
Common stock shares authorized	2,000,000	2,000,000
Common stock shares issued	835,500	817,900
Common stock shares outstanding	695,500	701,500
Preferred stock, no par value	$ 0	$ 0
Preferred stock, shares authorized	15,000	0
Preferred stock, shares issued	1,650	0
Preferred stock, shares outstanding	1,650	0
Preferred stock, dividend rate, percentage	4.75%