Note 9 - Net Income (Loss) Per Share (Tables)

12 Months Ended

Dec. 31, 2017

Notes Tables

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	Year Ended December 31,
	2017		2016		2015
Numerator:
Net Income  (loss)	$	29,993	$	2,577	$	(4,440	)
Denominator:
Weighted-average shares outstanding in basic calculation		13,873		13,225		13,960
Add: dilutive effect of potential common shares		855		528		—
Weighted-average shares used in computing diluted net income per share		14,728		13,753		13,960
Net income  (loss) per share:
Net income (loss) per share, basic	$	2.16	$	0.19	$	(0.32	)
Net income (loss) per share, diluted	$	2.04	$	0.19	$	(0.32	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	Year Ended December 31,
	201 7		201 6		201 5
Options to purchase common stock		42		220		2,575
Restricted stock units		9		24		296
Employee stock purchase plan shares		—		—		93
Performance stock units		—		—		24
Total		51		244		2,988