Consolidated Balance Sheets (unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Line of Credit Facility [Line Items]
Unamortized Debt Issuance Expense		$ 18.1
Assets
Trade receivables, allowances	$ 27.9	23.2
Property and equipment, accumulated depreciation	470.2	449.2
Identified intangibles, with finite useful lives, accumulated amortization	148.8	139.0
Investments in real estate ventures accounted for at fair value	$ 202.3	$ 155.2
Company shareholders' equity
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	45,116,507	45,049,503
Common stock, shares outstanding (in shares)	45,116,507	45,049,503
Line of Credit [Member]
Line of Credit Facility [Line Items]
Unamortized Debt Issuance Expense	$ 14.5	$ 15.4
Long-Term Senior Notes [Member]
Line of Credit Facility [Line Items]
Unamortized Debt Issuance Expense	$ 2.6	$ 2.7