Consolidated Balance Sheets (unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets
Trade receivables, allowances	$ 24,431	$ 18,783
Property and equipment, accumulated depreciation	416,810	374,030
Identified intangibles, with finite useful lives, accumulated amortization	123,510	116,393
Investments in real estate ventures accounted for at fair value	$ 101,018	$ 78,941
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)	44,817,758	44,447,958
Common stock, shares outstanding (in shares)	44,817,758	44,447,958