Condensed Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($) $ in Millions |
Sep. 30, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Current assets: | ||
| Allowance for doubtful accounts | $ 7.4 | $ 10.9 |
| Stockholders' equity: | ||
| Common stock, par value (in dollars per share) | $ 0.01 | $ 0.01 |
| Common stock, shares authorized (in shares) | 100,000,000 | 100,000,000 |
| Common stock, shares issued (in shares) | 52,221,054 | 51,953,354 |
| Common stock, shares outstanding (in shares) | 46,196,244 | 46,116,670 |
| Treasury stock, shares (in shares) | 6,024,810 | 5,836,684 |
| Commitments and Contingencies |