CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Current Assets
Allowance for doubtful accounts	$ 121.6	$ 128.1
Other Assets
Accumulated amortization on intangible assets	$ 441.3	$ 425.4
Shareholders' Equity
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	25,000,000	25,000,000
Preferred stock, issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	125,000,000	125,000,000
Common stock, issued (in shares)	117,762,065	117,555,991
Treasury stock at cost (in shares)	64,165,136	61,990,021