CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts	$ 44,730	$ 59,689
Preferred stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	5,000,000	4,175,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	250,000,000	125,000,000
Common stock, shares issued (in shares)	117,682,543	71,421,664
Common stock, shares outstanding (in shares)	117,682,543	68,767,613
Treasury stock (in shares)	0	2,654,051
Series A Preferred Stock
Convertible preferred stock series, par value (in USD per share)	$ 0.0001	$ 0.0001
Convertible preferred stock series, shares authorized (in shares)	825,000	825,000
Convertible preferred stock series, shares issued (in shares)	21,645	635,822
Convertible preferred stock series, shares outstanding (in shares)	21,645	635,822
Convertible preferred stock series, liquidation preference	$ 2,603	$ 69,702
Series C Preferred Stock
Convertible preferred stock series, par value (in USD per share)	$ 0.0001
Convertible preferred stock series, shares authorized (in shares)	625,000
Convertible preferred stock series, shares issued (in shares)	614,177
Convertible preferred stock series, shares outstanding (in shares)	614,177
Convertible preferred stock series, liquidation preference	$ 75,491