Note 6 - Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2016

Notes Tables

Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block]

	Year Ended December 31,
	2016			2015			2014
Stock-based compensation expense, gross	$	5,099		$	4,019		$	5,012
Income tax benefit at our statutory rate associated with stock-based compensation		(1,989	)		(1,567	)		(1,955	)
Stock-based compensation expense, net	$	3,110		$	2,452		$	3,057

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

	Year Ended December 31,
	2016					2015					2014
				Weighted-					Weighted-					Weighted-
				Average					Average					Average
	Number			Grant Date		Number			Grant Date		Number			Grant Date
	of			Fair Value		of			Fair Value		of			Fair Value
	Shares			Per Share		Shares			Per Share		Shares			Per Share
Restricted stock - common:
Outstanding - beginning of period		337,506		$	9.57		385,056		$	9.09		274,838		$	4.43
Granted		237,500			12.88		150,308			10.27		312,961			11.78
Vested		(178,973	)		8.46		(197,858	)		9.16		(202,743	)		6.93
Outstanding - end of period		396,033		$	12.06		337,506		$	9.57		385,056		$	9.09

	Year Ended December 31,
	2016					2015					2014
				Weighted-					Weighted-					Weighted-
				Average					Average					Average
	Number			Grant Date		Number			Grant Date		Number			Grant Date
	of			Fair Value		of			Fair Value		of			Fair Value
	Shares			Per Share		Shares			Per Share		Shares			Per Share
Restricted stock - Class A common:
Outstanding - beginning of period		374,693		$	9.46		204,473		$	9.81		-		$	-
Granted		218,612			11.25		287,513			9.37		236,294			9.80
Vested		(178,223	)		10.04		(117,293	)		9.85		(31,821	)		9.75
Outstanding - end of period		415,082		$	10.15		374,693		$	9.46		204,473		$	9.81