Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2012

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

	2010					2011					2012
Volatility		40.08	–	44.31	%		35.79	–	44.46	%		45.86	–	48.36	%
Expected life (years)		6.50	–	8.00				6.00					6.00
Risk-free interest rate		1.62	–	3.53	%		1.21	–	2.54	%		0.83	–	1.15	%
Dividend yield			—					—					—
Fair value	$	0.63	–	4.32		$	3.39	–	9.28		$	4.23	–	6.54

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

	Number of options			Weighted average exercise price		Weighted average remaining contractual life (years)		Aggregate intrinsic value (in thousands)
Outstanding at December 31, 2009		1,323,782		$	3.02
Options granted		4,172,687			8.45
Options forfeited		(242,633	)		6.88
Options exercised		(195,311	)		3.50
Outstanding at December 31, 2010		5,058,525		$	7.29
Options granted		3,173,900			19.64
Options forfeited		(402,220	)		12.22
Options exercised		(458,901	)		5.00
Outstanding at December 31, 2011		7,371,304		$	12.48
Options granted		2,933,701			10.28
Options forfeited		(552,228	)		15.28
Options exercised		(289,120	)		8.46
Outstanding at December 31, 2012		9,463,657		$	11.76		8.1	$	39,382
Exercisable at December 31, 2012		4,178,446		$	9.62		7.3	$	24,390
Expected to vest after December 31, 2012		4,703,838		$	13.48		8.8	$	13,343

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

	Level 1		Level 2		Level 3		Total
As of December 31, 2011
Financial instruments:
Interest rate swap	$	—	$	326	$	—	$	326
Contingent consideration		—		—		1,621		1,621
As of December 31, 2012
Financial instruments:
Interest rate swap	$	—	$	101	$	—	$	101
Contingent consideration		—		—		846		846