CONSOLIDATED BALANCE SHEETS (Paranthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Allowance for doubtful accounts receivable (in dollars)	$ 3,631	$ 3,719
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares outstanding	0	0
Common Class A [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	2,719,860	2,731,860
Common stock, shares outstanding	2,719,860	2,731,860
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	2,861,843	2,861,843
Common stock, shares outstanding	2,861,843	2,861,843
Common Class C [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	3,121,048	3,121,048
Common stock, shares outstanding	3,121,048	3,121,048
Common Class D [Member]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares issued	41,421,667	41,409,667
Common stock, shares outstanding	41,421,667	41,409,667