Note 4 - Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Notes Tables

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

	201 7						201 6
	Class A			Class B			Class A			Class B
Expected dividend yield at date of grant		2.87	%		7.99	%		3.02	%		8.12	%
Expected stock price volatility		32.20	%		27.18	%		34.61	%		31.77	%
Risk-free interest rate		2.33	%		2.33	%		2.12	%		2.12	%
Expected life of options (in years)		8			8			8			8

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, 201 6		1,705,483		$	12.31
Granted		119,917		$	18.80
Exercised		(97,068	)	$	13.10			$	590
Forfeit ed		--			--
Outstanding at March 31, 2017		1,728,332		$	12.72		6.00	$	12,064
Exercisable at March 31, 2017		1,195,077		$	11.49		4.76	$	9,807
Class B
Outstanding at December 31, 2016		250,493		$	29.70
Granted		19,986		$	40.54
Exercised		(12,000	)	$	28.41			$	142
Forfeited		--			--
Outstanding at March 31, 2017		258,479		$	30.60		6.38	$	2,402
Exercisable at March 31, 2017		170,550		$	27.52		5.14	$	2,140

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, 2016		174,487	$	13.93		29,081	$	37.21
Granted		--		--		--		--
Vested		--		--		--		--
Forfeited		--		--		--		--
Outstanding at March 31, 2017		174,487	$	13.93		29,081	$	37.21