Condensed Consolidated Balance Sheets [Parenthetical] - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Adjustments for chargebacks and other allowances	$ 50,603	$ 34,686
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 0.0001	$ 0.0001
Preferred Stock, Shares Authorized	1,666,667	1,666,667
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0
Treasury Stock, Common, Shares	11,179	5,203
Common Stock [Member]
Common Stock, Par Value (in dollars per share)	$ 0.0001	$ 0.0001
Common Stock, Authorized Shares	33,333,334	33,333,334
Common Stock, Issued Shares	11,857,914	11,655,768
Common Stock, Outstanding Shares	11,846,735	11,650,565
Class C Special Stock [Member]
Common Stock, Par Value (in dollars per share)	$ 0.0001	$ 0.0001
Common Stock, Authorized Shares	781,281	781,281
Common Stock, Issued Shares	10,864	10,864
Common Stock, Outstanding Shares	10,864	10,864