CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Allowance for doubtful accounts	$ (51,072,000)	$ (59,689,000)
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	4,175,000	4,175,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	125,000,000	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, shares (in shares)	0	2,654,051
Series A Preferred Stock
Convertible preferred stock series, par value (in dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock series, liquidation preference	$ 2,530,000	$ 69,702,000
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
Series C Preferred Stock
Convertible preferred stock series, par value (in dollars per share)	$ 0.0001	$ 0
Convertible preferred stock series, liquidation preference	$ 73,365,000	$ 0
Convertible preferred stock series, shares authorized (in shares)	625,000	0
Convertible preferred stock series, shares issued (in shares)	614,177	0
Convertible preferred stock series, shares outstanding (in shares)	614,177	0