Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2013

Accounting Policies [Abstract]

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

	2011					2012					2013
Volatility		35.79	–	44.46	%		45.86	–	48.36	%		48.37	–	49.10	%
Expected life (years)			6.00					6.00					6.00
Risk-free interest rate		1.21	–	2.54	%		0.83	–	1.15	%		0.97	–	1.73	%
Dividend yield			—					—					—
Fair value	$	3.39	–	9.28		$	4.23	–	6.54		$	6.63	–	12.61

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, 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
Options granted		621,100			18.16
Options forfeited		(520,139	)		15.38
Options exercised		(2,229,873	)		10.85
Outstanding at December 31, 2013		7,334,745		$	12.33		7.3	$	128,711
Exercisable at December 31, 2013		4,737,944		$	11.29		6.8	$	88,008
Expected to vest after December 31, 2013		2,207,281		$	14.20		8.2	$	34,598

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

	Number of awards			Weighted average grant date fair value
Non-vested awards at December 31, 2010		75,409		$	7.15
Awards granted		31,200			13.62
Awards vested		(64,186	)		6.06
Awards forfeited		—			—
Non-vested awards at December 31, 2011		42,423		$	13.55
Awards granted		187,270			13.73
Awards vested		(40,281	)		13.74
Awards forfeited		—			—
Non-vested awards at December 31, 2012		189,412		$	13.68
Awards granted		668,885			15.78
Awards vested		(77,513	)		13.30
Awards forfeited		(26,570	)		14.06
Non-vested awards at December 31, 2013		754,214		$	15.57

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, 2012
Financial instruments:
Interest rate swap	$	—	$	(101	)	$	—		$	(101	)
Contingent consideration		—		—			(846	)		(846	)
As of December 31, 2013
Financial instruments:
Contingent consideration	$	—	$	—		$	(4,834	)	$	(4,834	)
Foreign currency derivative asset		—		61			—			61
Foreign currency derivative liability		—		(683	)		—			(683	)

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	Foreign Currency Translation			Net investment hedge - foreign exchange contract			Net investment hedge - Australian denominated debt			Total
Balance at December 31, 2011	$	(1,429	)	$	—		$	—		$	(1,429	)
Change during 2012:
Before-tax amount		5,798			—			(285	)		5,513
Tax (expense) benefit		(1,013	)		—			112			(901	)
Total activity in 2012		4,785			—			(173	)		4,612
Balance at December 31, 2012	$	3,356		$	—		$	(173	)	$	3,183
Change during 2013:
Before-tax amount		(14,706	)		799			626			(13,281	)
Tax (expense) benefit		4,725			(316	)		(248	)		4,161
Total activity in 2013		(9,981	)		483			378			(9,120	)
Balance at December 31, 2013	$	(6,625	)	$	483		$	205		$	(5,937	)