Consolidated Balance Sheets (Parenthetical) (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Trade receivables, allowance for doubtful accounts	$ 4,286	$ 3,926
Prepaid expenses and other current assets (including related parties of $274 and $274)	5,697	5,939
Intangible assets subject to amortization, net (including related parties of $22,039 and $23,513)	23,067	24,598
Accounts payable and accrued expenses (including related parties of $3,891 and $5,691)	37,466	39,750
Long-term debt, less current maturities, bond discount	3,641	4,134
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	54,354,226	53,514,769
Common stock, shares outstanding	54,354,226	53,514,769
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	22,188,161	22,188,161
Common stock, shares outstanding	22,188,161	22,188,161
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
Related Parties
Trade receivables, related parties	8,914	5,608
Prepaid expenses and other current assets (including related parties of $274 and $274)	274	274
Intangible assets subject to amortization, net (including related parties of $22,039 and $23,513)	22,039	23,513
Accounts payable and accrued expenses (including related parties of $3,891 and $5,691)	$ 3,891	$ 5,691