Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accounts and notes receivable, allowances	$ 8.4	$ 10.3
Common stock, par value (per share)	$ 0.01	$ 0.01
Common stock, shares authorized	426,000,000.0	426,000,000.0
Common stock, shares issued	166,100,000	168,300,000