CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Statement Of Financial Position [Abstract]
Accounts receivable - trade, allowance for doubtful accounts	$ 12.3	$ 10.4
Property and equipment, accumulated depreciation	352.0	289.0
Identifiable intangible assets, accumulated amortization	$ 209.4	$ 179.8
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	105,900,000	105,700,000