Consolidated Balance Sheets (Parentheticals) - USD ($) $ / shares in Thousands, $ in Thousands |
Dec. 31, 2018 |
Dec. 31, 2017 |
---|---|---|
Accounts receivable, allowance for doubtful accounts | $ 5,346 | $ 4,606 |
Common stock, par value (in dollars per share) | $ 0 | $ 0 |
Common stock, shares authorized (in shares) | 200,000,000 | 100,000,000 |
Common stock, shares issued (in shares) | 89,298,943 | 88,788,664 |
Common stock, shares outstanding (in shares) | 82,022,500 | 83,253,588 |
Treasury stock (in shares) | 7,276,443 | 5,535,076 |
Common Class A [Member] | ||
Common stock, par value (in dollars per share) | $ 0 | $ 0 |
Common stock, shares authorized (in shares) | 25,000,000 | 15,000,000 |
Common stock, shares issued (in shares) | 8,569,149 | 8,349,069 |
Common stock, shares outstanding (in shares) | 6,729,035 | 6,598,377 |
Treasury stock (in shares) | 1,840,114 | 1,750,692 |