CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowances for credit losses	$ 20.9	$ 18.5	$ 24.3
Common stock, par value (USD per share)	$ 1.00	$ 1.00	$ 1.00
Common stock authorized (in shares)	1,000,000,000	1,000,000,000	1,000,000,000
Common stock issued (in shares)	441,400,000	441,400,000	441,400,000