Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Allowance for doubtful accounts	$ 32,471	$ 29,202
Preferred stock par value	$ 0.0001	$ 0.0001
Preferred stock authorized	7,500,000	7,500,000
Preferred stock issued	0	0
Preferred stock outstanding	0	0
Common Class A [Member]
Common stock par value	$ 0.0001	$ 0.0001
Common stock authorized	80,000,000	80,000,000
Common stock issued	23,680,749	23,332,532
Common stock outstanding	23,680,627	23,332,410
Common Class B [Member]
Common stock par value	$ 0.0001	$ 0.0001
Common stock authorized	20,000,000	20,000,000
Common stock issued	5,096,780	5,149,771
Common stock outstanding	5,095,863	5,148,854
Treasury Class-A [Member]
Treasury Stock, Shares	122	122
Treasury Class B [Member]
Treasury Stock, Shares	917	917