Note 13 - Accounting for Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

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

	Stock-Based Compensation
	Recognized December 31,						Unrecognized
	2016		2015		2014		December 31, 2016		Weighted- Average Period to Recognize (years)
Stock Options	$	909	$	1,546	$	1,866	$	134		0.2
Restricted Stock Units		6,325		7,409		7,881		14,030		2.4
Cash-Settled Restricted Stock Units		7,091		4,414		3,207		17,114		2.7
Non-Employee Director Awards		741		645		481		—		—
Performance Shares		877		727		—		2,346		1.6
	$	15,943	$	14,741	$	13,435	$	33,624

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

	Number of Shares			Weighted Average Exercise Price		Aggregate Intrinsic Value (in thousands)
Outstanding at January 1, 2014		694,552		$	24.34
Exercised		(85,063	)	$	21.53
Granted		166,861		$	40.68
Forfeited/Expired		(9,426	)	$	25.53
Outstanding at December 31, 2014		766,924		$	28.20
Exercised		(43,919	)	$	21.23
Granted		—		$	—
Forfeited/Expired		—		$	—
Outstanding at December 31, 2015		723,005		$	28.62
Exercised		(128,301	)	$	23.65
Granted		—		$	—
Forfeited/Expired		(7,297	)	$	40.68
Outstanding at December 31, 2016		587,407		$	29.56	$	15,064
Vested plus expected to vest at December 31, 2016		587,204		$	29.55	$	15,061
Exercisable at December 31, 2016		535,376		$	28.47	$	14,308

Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block]

			OPTIONS OUTSTANDING						OPTIONS EXERCISABLE
Range of Exercise Prices			Number Outstanding As of December 31, 2016		Weighted Average Remaining Contractual Term		Weighted Average Exercise Price		Number Exercisable As of December 31, 2016		Weighted Average Exercise Price
$ 9.05	–	$25.00		131,267		3.7	$	23.37		131,267	$	23.37
$25.01	–	$28.00		300,107		5.8	$	26.48		300,107	$	26.48
$28.01	–	$41.00		156,033		7.1	$	40.68		104,002	$	40.68
$9.05	to	$41.00		587,407		5.7	$	29.56		535,376	$	28.47

Schedule of Share-based Compensation, Nonemployee Director Stock Award Plan, Activity [Table Text Block]

For the Year ended December 31,	Number of Shares Granted		Weighted- Average Grant Date Fair Value
2014		15,872	$	36.08
2015		18,109	$	35.62
201 6		15,299	$	39.32

Share-based Compensation, Performance Shares Award Unvested Activity [Table Text Block]

				Weighted-
	Number of Shares			Average Grant Date Fair Value		Aggregate Intrinsic Value (in thousands)
Non-vested PSAs at January 1, 2015		—			—
Granted		58,822		$	44.21
Vested		—			—
Cancelled		—			—
Non-vested PSAs at December 31, 2015		58,822		$	44.21
Granted		74,574		$	37.75
Vested		—			—
Cancelled		(3,422	)	$	41.61
Non-vested PSAs at December 31, 2016		129,974		$	40.57	$	7,175
PSA s expected to vest in the future		129,974		$	40.57	$	7,175

Cash Settled RSUs [Member]

Notes Tables

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

				Weighted-
	Number of Shares			Average Grant Date Fair Value		Aggregate Intrinsic Value (in thousands)
Non-vested CSRSUs at January 1, 2014		200,299		$	28.23
Granted		416,432		$	39.12
Vested		(47,742	)	$	27.55
Cancelled		(31,870	)	$	32.12
Non-vested CSRSUs at December 31, 2014		537,119		$	36.36
Granted		121,015		$	39.35
Vested		(78,033	)	$	33.29
Cancelled		(133,438	)	$	38.14
Non-vested CSRSUs at December 31, 2015		446,663		$	37.18
Granted		233,790		$	34.29
Vested		(146,619	)	$	34.70
Cancelled		(70,812	)	$	37.55
Non-vested CSRSUs at December 31, 2016		463,022		$	35.96	$	25,559
CSRSUs expected to vest in the future		463,022		$	35.96	$	25,559

Restricted Stock Units (RSUs) [Member]

Notes Tables

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

	Number of Shares			Weighted- Average Grant Date Fair Value		Aggregate Intrinsic Value (in thousands)
Non-vested RSUs at January 1, 2014		756,188		$	25.13
Granted		265,811		$	39.48
Vested		(333,321	)	$	24.73
Cancelled		(44,791	)	$	27.33
Non-vested RSUs at December 31, 2014		643,887		$	31.10
Granted		250,159		$	39.04
Vested		(233,899	)	$	26.85
Cancelled		(104,243	)	$	36.76
Non-vested RSUs at December 31, 2015		555,904		$	35.40
Granted		240,868		$	34.68
Vested		(221,659	)	$	32.45
Cancelled		(67,115	)	$	37.60
Non-vested RSUs at December 31, 2016		507,998		$	36.12	$	28,041
RSUs expected to vest in the future		507,998		$	36.12	$	28,041