Note 15 - Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2013

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

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
Shares issuable under options - December 31, 2010		1,850,300		$	19.03
Granted		308,000			30.78
Exercised		(262,750	)		19.87
Shares issuable under options - December 31, 2011		1,895,550		$	20.83
Granted		367,000			31.48
Exercised		(363,850	)		19.15
Forfeited		(169,500	)		32.38
Shares issuable under options - December 31, 2012		1,729,200		$	22.31
Granted		422,000			31.35
Exercised		(464,150	)		16.20
Shares issuable under options - December 31, 2013		1,687,050		$	26.25		2.5	$	28,345
Options exercisable - End of period		709,350		$	21.97		1.6	$	14,950

Stock Options Exercised {Table Text Block]

	2013		2012		2011
Number of options exercised		464,150		363,850		262,750
Aggregate fair value	$	16,780	$	11,198	$	8,510
Intrinsic value		9,313		4,265		3,320
Amount of cash received		7,467		6,933		5,190
Tax benefit recognized	$	3,148	$	1,438	$	1,119

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

	2013			2012			2011
Risk free rate		0.4	%		0.4	%		1.0	%
Expected life in years		4.75			4.75			4.75
Expected volatility		37.5	%		40.3	%		39.4	%
Dividend yield		0.0	%		0.0	%		0.0	%
Weighted average fair value per option granted	$	10.13		$	10.87		$	10.73