Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Allowances for accounts receivable	$ 16.5	$ 18.1
Preferred stock, shares authorized (class I & class II preferred stock)	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Company common stock shares authorized	200,000,000	200,000,000
Common stock, shares issued	75,834,668	98,375,135
Treasury shares	158,836	22,836,180