Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Trade receivables, allowance for doubtful accounts	$ 3,162	$ 3,040
Trade receivables, related parties	5,116	5,534
Prepaid expenses and other current assets	6,602	5,705
Property and equipment, accumulated depreciation	203,030	198,282
Accumulated amortization of Intangible assets	80,885	78,234
Intangible assets subject to amortization, net	14,005	16,656
Accounts payable and accrued expenses	28,440	29,787
Unamortized debt issuance costs	2,704	3,226
Related Parties
Prepaid expenses and other current assets	274	274
Intangible assets subject to amortization, net	12,178	13,918
Accounts payable and accrued expenses	$ 3,955	$ 3,791
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	65,401,179	64,477,171
Common stock, shares outstanding	65,401,179	64,477,171
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	14,927,613
Common stock, shares outstanding	14,927,613	14,927,613
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