Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Accounts receivable, allowance	$ 927	$ 388
Property and equipment, accumulated depreciation and amortization	83,044	73,068
Software development costs, accumulated amortization	2,686	1,791
Acquired intangible assets, accumulated amortization	$ 13,021	$ 10,173
Class A Common Stock
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	225,000,000	225,000,000
Common Stock, shares issued	54,723,418	53,763,871
Common Stock, shares outstanding	54,723,418	53,763,871
Class B Common Stock
Common Stock, par value	$ 0.01	$ 0.01
Common Stock, shares authorized	75,000,000	75,000,000
Common Stock, shares issued	4,901,245	4,997,769
Common Stock, shares outstanding	4,901,245	4,997,769