CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 65.2	$ 49.6
Property, plant and equipment, accumulated depreciation	603.2	495.2
Intangible assets, accumulated amortization	$ 392.5	$ 271.6
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	673,380	726,500
Preferred stock, outstanding (in shares)	673,380	726,500
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized (in shares)	120,000,000	120,000,000
Common stock, issued (in shares)	85,500,000	85,200,000
Common stock, outstanding (in shares)	85,500,000	85,200,000