CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts, current	$ 8.3	$ 7.7
Stockholders' Equity
Common shares authorized (in shares)	400,000,000	400,000,000
Common shares issued (in shares)	258,300,000	289,300,000
Treasury stock (in shares)	1,700,000	300,000