Note 11 - Employee Benefit Plans (Details Textual) - USD ($)
|
12 Months Ended |
|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2011 |
| Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent |
15.00%
|
|
|
|
| Defined Contribution Plan, Employer Matching Contribution, Percent of Match |
50.00%
|
|
|
|
| Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay |
3.00%
|
|
|
|
| Defined Contribution Plan, Cost Recognized |
$ 254,000
|
$ 208,000
|
$ 119,000
|
|
| 2011 Equity Incentive Plan [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized |
|
|
|
500,000
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Other Increases (Decreases) in Period |
|
204,807
|
102,586
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term |
4 years
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross |
0
|
0
|
0
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term |
4 years
|
|
|
|
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options |
$ 0
|
|
|
|
| 2011 Equity Incentive Plan [Member] | Performance Shares [Member] |
|
|
|
|
| Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period |
4 years
|
|
|
|
| Allocated Share-based Compensation Expense |
$ 826,000
|
$ 680,000
|
$ 358,000
|
|
| Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options |
1,603,000
|
|
|
|
| 2011 Equity Incentive Plan [Member] | Employee Stock Option [Member] |
|
|
|
|
| Allocated Share-based Compensation Expense |
$ 0
|
$ 0
|
$ 0
|
|