Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2011

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

	2009					2010					2011
Volatility		45.06	-	47.87	%		40.08	-	44.31	%		35.79	-	44.46	%
Expected life (years)				8.00			6.50	-	8.00					6.00
Risk-free interest rate		2.64	-	3.30	%		1.62	-	3.53	%		1.21	-	2.54	%
Dividend yield				—					—					—
Fair value	$	0.66	-	1.02		$	0.63	-	4.32		$	3.39	-	9.28

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

	Number of options			Weighted average exercise price		Weighted average remaining contractual life		Aggregate intrinsic value
Outstanding at December 31, 2008		817,116		$	2.80
Options granted		772,239			3.20
Options forfeited		(265,573	)		2.89
Options exercised		—			—
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	8.66	years	$	12,725,000
Exercisable at December 31, 2011		2,281,246		$	6.06	7.83	years	$	8,745,000
Expected to vest after December 31, 2011		4,682,853		$	15.36	9.04	years	$	3,669,000

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, 2010:
Financial liabilities:
Interest rate swap	$	—	$	654	$	—	$	654
Contingent consideration		—		—		6,202		6,202
As of December 31, 2011:
Financial liabilities:
Interest rate swap	$	—	$	326	$	—	$	326
Contingent consideration		—		—		1,621		1,621