Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Trade receivables, allowance for doubtful accounts	$ 2,890	$ 3,199
Trade receivables, related parties	10,791	7,102
Prepaid expenses and other current assets	6,157	4,087
Property and equipment, accumulated depreciation	191,336	184,084
Finite lived intangible assets, accumulated amortization	73,813	71,678
Finite lived intangible assets subject to amortization	21,077	19,812
Accounts payable and accrued expenses	29,583	31,246
Related Parties
Prepaid expenses and other current assets	274	274
Finite lived intangible assets subject to amortization	16,819	18,559
Accounts payable and accrued expenses	$ 3,778	$ 3,994
Class A common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	260,000,000	260,000,000
Common stock, shares issued	60,303,868	59,793,603
Common stock, shares outstanding	60,303,868	59,793,603
Treasury stock, shares	772,772	0
Class B common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	18,930,035	18,969,222
Common stock, shares outstanding	18,930,035	18,969,222
Class U common stock
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	40,000,000	40,000,000
Common stock, shares issued	9,352,729	9,352,729
Common stock, shares outstanding	9,352,729	9,352,729