Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Accounts receivable allowance | $ 5,901 | $ 4,380 |
| Common stock, shares authorized (in shares) | 40,000,000 | 40,000,000 |
| Common stock, par value (in dollars per share) | $ 0.001 | $ 0.001 |
| Common stock, shares issued (in shares) | 17,315,661 | 17,186,780 |
| Common stock, shares outstanding (in shares) | 17,315,661 | 17,186,780 |
| Treasury shares, shares (in shares) | 3,478,676 | 1,895,998 |
| Convertible Preferred Stock [Member] | ||
| Convertible Preferred Stock, Shares Authorized (in shares) | 10,000,000 | 10,000,000 |
| Convertible Preferred Stock, Par Value (in dollars per share) | $ 0.001 | $ 0.001 |
| Convertible Preferred Stock, Shares Issued (in shares) | 803,398 | 803,518 |
| Convertible Preferred Stock, Shares Outstanding (in shares) | 803,398 | 803,518 |
| Convertible Preferred Stock [Member] | Cash Dividends [Member] | ||
| Convertible Preferred Stock, Dividend Rate | 5.50% | 8.50% |