Note 13 - Convertible Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule of Stock by Class [Table Text Block]

	Shares				Liquidation amount		Carrying Value
	Authorized		Outstanding
Series A		7,703,785		20,923,195	$	3,082	$	3,082
Series B		2,567,390		6,972,887		2,567		2,567
Series C		3,256,601		8,606,455		1,806		1,806
Series D		11,773,243		31,004,350		11,415		11,425
Series E		2,212,960		6,010,107		3,319		3,319
Series F		15,988,145		36,983,520		23,830		23,831
Total convertible preferred stock		43,502,124		110,500,514	$	46,019	$	46,030