Note 10 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Notes Tables

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

	Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms		Aggregate Intrinsic Value
	(shares and aggregate intrinsic value in thousands)
Outstanding at December 31, 2014		4,101		$	18.72
Granted		2,442			14.69
Exercised		(578	)		7.25
Forfeitures		(560	)		21.53
Expired		(375	)		24.10
Outstanding at December 31, 2015		5,030			17.37		5.10		3,728
Expected to vest at December 31, 2015		3,104			16.42		6.22		714
Exercisable at December 31, 2015		1,857		$	18.98		3.19	$	2,999

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

	Years ended December 31,
	2015			2014			2013
Expected dividend yield		0	%		0	%		0	%
Risk-free interest rate		1.54	%		1.57	%		1.21	%
Expected volatility		40.62	%		38.18	%		37.22	%
Expected life (years)		4.89			4.82			4.51

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

	Number of Units			Weighted Average Grant Date Fair Value per Share		Aggregate Intrinsic Value
	(in thousands, except for weighted average grant date fair value per unit)
Outstanding balance at December 31, 2014		910		$	22.84
Granted		727			16.23
Vesting of restricted stock units, net of shares withheld for taxes		(174	)		23.22
Shares withheld for taxes		(71	)		23.22
Forfeitures		(238	)		21.60
Outstanding balance at December 31, 2015		1,154		$	18.85	$	14,274