Consolidated Balance Sheets (Parentheticals) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Trade accounts receivable, allowance for doubtful accounts (in Dollars)	$ 5,475	$ 2,772
Total assets of variable interest entities(VIE) (in Dollars)	175,900	41,100
Total liabilities of VIEs (in Dollars)	$ 10,800	$ 10,600
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares outstanding (in Dollars per share)	$ 0	$ 0
Preferred stock par value (in Dollars per share)	$ 0	$ 0
Common stock, par value (in Dollars per share)	$ 0	$ 0
Voting Common Stock [Member]
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	129,931,812	87,695,495
Nonvoting Common Stock [Member]
Common stock, shares authorized		400,000,000
Common stock, shares issued		828,885