XML 76 R62.htm IDEA: XBRL DOCUMENT v3.10.0.1
Note 13 - Equity Incentive Plan (Details Textual) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 12 Months Ended
Mar. 31, 2018
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Jun. 13, 2017
Jun. 18, 2013
Jun. 07, 2011
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value   $ 20.01 $ 16.87 $ 16.65      
Allocated Share-based Compensation Expense, Total   $ 11,046 $ 5,807 $ 3,392      
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense   $ 1,500 400 600      
Share-based Compensation Arrangement by Share-based Payment Award Options and Stock Appreciation Rights Vested and Expected to Vest Outstanding Weighted Average Exercise Price   $ 42.06          
Share-based Compensation Arrangement by Share-based Payment Award Options and Stock Ppreciation Rights Vested and Expected to Vest Outstanding Aggregate Intrinsic Value   $ 5,000          
Share-based Compensation Arrangement by Share-based Payment Award, Options and Stock Appreciation Rights, Exercises in Period, Total Intrinsic Value   8,500 500 2,100      
Share-based Compensation Arrangement by Share-based Payment Award Options and Stock Appreciation Rights Vested in Period Fair Value   $ 6,700 2,100 1,300      
Chief Executive Officer [Member]              
Allocated Share-based Compensation Expense, Total $ 6,200            
Employee Stock Option [Member]              
Share-based Compensation Arrangement Evaluation of Expected Volatility Assumption to Historical Volatility Average Period   4 years 182 days          
Stock Options, SARs and Restricted Stock Awards [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number, Ending Balance   1,136,914          
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Total   $ 4,400          
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition   2 years 146 days          
Restricted Stock and Restricted Stock Units [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value   $ 6,800 $ 2,300 $ 1,000      
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value   $ 58.84 $ 52.03 $ 38.11      
The 2017 Plan [Member]              
Number of Shares Available for Grant Reduced By Each Share Award Issued Other Than Options or SARs         2    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized         1,200,000    
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant   900,000          
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period   10 years          
The 2017 Plan [Member] | Minimum [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   1 year          
The 2017 Plan [Member] | Maximum [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period   4 years          
Amended Two Thousand Three Plan [Member]              
Number of Shares Available for Grant Reduced By Each Share Award Issued Other Than Options or SARs             1.9
Second Amended Two Thousand Three Plan [Member]              
Number of Shares Available for Grant Reduced By Each Share Award Issued Other Than Options or SARs           1.5