Note 10 - Share Option and Equity Incentive Plan (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	201 6		201 5		201 4
Expected dividend yield (%)		—		—		—
Expected volatility (%)		43.70		44.11		46.87
Risk-free interest rate (%)		1.53		1.66		1.86
Expected life of option (years)		6.16		6.19		6.19
Weighted-average share price ($)		10.29		14.15		19.66
Weighted-average exercise price ($)		10.29		14.15		19.66
Model used		Black-Scholes Model		Black-Scholes Model		Black-Scholes Model

Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block]

	Number of ordinary shares			WAEP
Outstanding as of January 1, 2016		2,425,426		$	9.03
Granted		749,964			10.29
Exercised		(85,943	)		0.82
Forfeited		(239,667	)		14.27
Outstanding as of December 31, 2016		2,849,780			9.15
Vested or expected to vest as of December 31, 2016		2,790,851		$	9.08
Exercisable as of December 31, 2016		1,671,179		$	6.81

Nonvested Restricted Stock Shares Activity [Table Text Block]

	Number of ordinary shares			WAFV
Unvested balance as of January 1, 2016		366,739		$	19.72
Granted		108,361			10.21
Cancelled		(57,530	)		16.17
Vested		(88,105	)		22.99
Unvested balance as of December 31, 2016		329,465			16.34

Schedule of Nonvested Share Activity [Table Text Block]

	Number of shares			Weighted- average grant date fair value
Balance as of December 31, 2015		1,124,443		$	6.53
Granted		749,964			4.53
Vested		(479,295	)		5.92
Forfeited		(216,510	)		6.08
Balance as of December 31, 2016		1,178,602			5.61

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

(in thousands)	2016		2015		201 4
Cost of revenue	$	57	$	529	$	330
Research and development		548		86		87
Sales and marketing		1,725		1,045		949
General and administrative		2,689		1,825		1,155
Total share-based compensation	$	5,019	$	3,485	$	2,521