Note 6 - Share-based Compensation (Tables)

6 Months Ended

Jun. 30, 2019

Notes Tables

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Six Month Period Ended
	June 30, 2019
				Wtd. Avg.
				Exercise
	Options			Price
Outstanding at beginning of year		2,043,402		$	1.91
Granted		—		$	—
Exercised		(236,061	)	$	1.96
Forfeited		(3,438	)	$	5.69
Expired		—		$	—
Outstanding service vesting-based at June 30, 2019		1,803,903		$	1.90
Service vesting-based options exercisable at June 30, 2019		1,600,799		$	1.87

	Six Month Period Ended
	June 30, 2019
			Wtd. Avg.
			Exercise
	Options		Price
Outstanding at beginning of year		964,997	$	1.64
Granted		—	$	—
Exercised		—	$	—
Outstanding performance-based at June 30, 2019		964,997	$	1.64
Performance-based options exercisable at June 30, 2019		964,997	$	1.64

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

	Six Month Period Ended
	June 30, 2019
Service vesting-based restricted stock	Number of Restricted Shares			Grant-Date Fair Value
Outstanding at beginning of year		279,919		$	5.00
Granted		177,718		$	17.80
Vested		(86,142	)	$	4.51
Forfeited		(21,269	)	$	10.17
Outstanding at June 30, 2019		350,226		$	11.30

	Six Month Period Ended
	June 30, 2019
Performance-based restricted stock	Number of Restricted Shares		Grant-Date Fair Value
Outstanding at beginning of year		—	$	—
Expected to vest		123,851	$	17.79
Vested		—	$	—
Outstanding at June 30, 2019		123,851	$	17.79

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Month Period Ended				Six Month Period Ended
	June 30,				June 30,
(In thousands)	2019		2018		2019		2018
Research and development costs	$	97	$	65	$	177	$	130
Sales and marketing costs		131		69		297		138
General and administrative costs		350		191		677		382
Cost of product sales		68		49		101		98
Total	$	646	$	374	$	1,252	$	748