Note 5 - Share-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2013

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

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

	2013				2012
Expected dividend yield at date of grant		2.26	to	3.46%		2.63	to	3.98%
Expected stock price volatility		30.34	to	30.51%		29.10	to	31.70%
Risk-free interest rate		0.55	to	1.07%		0.56	to	1.15%
Expected life of options (in years)		4	to	6		4	to	6

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

	Number of Options			Weighted Average Exercise Price		Weighted Average Remaining Contractual Terms (Years)		Aggregate Intrinsic Value (In thousands)
Class A
Outstanding at December 31, 2012		1,367,754		$	8.45
Granted		232,344		$	15.98
Exercised		(119,253	)	$	2.20
Forfeited		--			--
Outstanding at June 30, 2013		1,480,845		$	10.14		6.92	$	11,642
Exercisable at June 30, 2013		729,975		$	8.87		5.78	$	6,665
Class B
Outstanding at December 31, 2012		227,959		$	18.45
Granted		38,718		$	29.35
Exercised		(19,875	)	$	13.20
Forfeited		--			--
Outstanding at June 30, 2013		246,802		$	20.58		6.92	$	3,453
Exercisable at June 30, 2013		121,662		$	18.68		5.78	$	1,978

Schedule of Nonvested Share Activity [Table Text Block]

	Class A Shares Outstanding		Class A Weighted Average Grant Date  Fair Value Per Share		Class B Shares Outstanding		Class B Weighted Average Grant Date Fair Value Per Share
Outstanding at December 31, 2012		60,609	$	5.77		10,101	$	34.65
Granted		--		--		--		--
Vested		--		--		--		--
Forfeited		--		--		--		--
Outstanding at June 30, 2013		60,609	$	5.77		10,101	$	34.65