CONSOLIDATED BALANCE SHEETS [Parenthetical] (USD $) In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Allowance for doubtful accounts receivable (in dollars)	$ 3,825	$ 4,393
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	2,249,809	2,574,291
Common stock, shares outstanding	2,249,809	2,574,291
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	2,928,906	3,121,048
Common stock, shares outstanding	2,928,906	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	39,678,352	39,013,638
Common stock, shares outstanding	39,678,352	39,013,638