Note 4 - Share-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2013

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

	2013			2012
Expected dividend yield at date of grant		3.46	%		3.98	%
Expected stock price volatility		30.51	%		29.10	%
Risk-free interest rate		1.07	%		1.15	%
Expected life of options (in years)		6			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)
Outstanding at December 31, 2012		455,918		$	30.34
Granted		29,448		$	52.42
Exercised		(39,751	)	$	13.21
Cancelled		--			--
Outstanding at March 31, 2013		445,615		$	33.33		6.85	$	10,909
Exercisable at March 31, 2013		195,325		$	26.74		5.28	$	6,068

Schedule of Nonvested Share Activity [Table Text Block]

	Shares Outstanding		Weighted Average Grant Date Fair Value Per Share
Outstanding at December 31, 2012		20,203	$	34.65
Granted		--		--
Vested		--		--
Forfeited		--		--
Outstanding at March 31, 2013		20,203	$	34.65