Note 5 - Share-based Compensation (Tables)

3 Months Ended

Mar. 31, 2016

Notes Tables

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

	2016						2015
	Class A			Class B			Class A			Class B
Expected dividend yield at date of grant		3.02	%		8.12	%		2.57	%		5.72	%
Expected stock price volatility		34.61	%		31.77	%		34.87	%		33.94	%
Risk-free interest rate		2.12	%		2.12	%		1.78	%		1.78	%
Expected life of options (in years)		8			8			7			7

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, 2015		1,485,738		$	11.65
Granted		135,620		$	15.23
Exercised		(33,234	)	$	5.12			$	336
Forfeited		--			--
Outstanding at March 31, 2016		1,588,124		$	12.09		6.22	$	5,731
Exercisable at March 31, 2016		1,089,942		$	11.14		5.12	$	4,997
Class B
Outstanding at December 31, 2015		240,673		$	26.31
Granted		22,603		$	34.00
Exercised		(24,043	)	$	15.70			$	435
Forfeited		--			--
Outstanding at March 31, 2016		239,233		$	28.10		6.57	$	1,923
Exercisable at March 31, 2016		157,150		$	26.02		5.48	$	1,679

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, 2015		183,814		$	12.78		30,635		$	36.93
Granted		20,578		$	15.23		3,430		$	34.00
Vested		(20,892	)	$	5.38		(3,482	)	$	32.31
Forfeited		--			--		--			--
Outstanding at March 31, 2016		183,500		$	13.89		30,583		$	37.13