Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Trade receivables, allowance for doubtful accounts	$ 2,875	$ 3,100
Trade receivables, related parties	4,965	10,882
Prepaid expenses and other current assets	5,350	5,295
Property and equipment, accumulated depreciation	198,726	193,532
Accumulated amortization of Intangible assets	76,465	74,697
Intangible assets subject to amortization, net	18,424	20,193
Accounts payable and accrued expenses	28,275	32,195
Related Parties
Prepaid expenses and other current assets	274	274
Intangible assets subject to amortization, net	15,078	16,239
Accounts payable and accrued expenses	$ 3,810	$ 3,695
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	63,734,828	58,893,970
Common stock, shares outstanding	63,734,828	58,893,970
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	14,927,613	18,930,035
Common stock, shares outstanding	14,927,613	18,930,035
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