| Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] |   |  |  |  |  |  |  |  |  |  |  |   | Current assets, net of cash |  | $ | 36 |  |  | $ | - |  |  | $ | 36 |  |   | Equipment and other long-term assets |  |  | 284 |  |  |  | - |  |  |  | 284 |  |   | Intangible assets: |  |  |  |  |  |  |  |  |  |  |  |  |   | Developed technology |  |  | 20,000 |  |  |  | (7,800 | ) |  |  | 12,200 |  |   | Goodwill |  |  | 9,790 |  |  |  | 3,792 |  |  |  | 13,582 |  |   | Total assets acquired |  |  | 30,110 |  |  |  | (4,008 | ) |  |  | 26,102 |  |   | Liabilities |  |  | 765 |  |  |  | (469 | ) |  |  | 296 |  |   | Deferred income taxes, net |  |  | 3,741 |  |  |  | (3,296 | ) |  |  | 445 |  |   | Net assets acquired |  | $ | 25,604 |  |  | $ | (243 | ) |  | $ | 25,361 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Cash paid, net of cash acquired |  | $ | 20,404 |  |  | $ | 57 |  |  | $ | 20,461 |  |   | Fair value of contingent consideration |  |  | 5,200 |  |  |  | (300 | ) |  |  | 4,900 |  |   | Net assets acquired |  | $ | 25,604 |  |  | $ | (243 | ) |  | $ | 25,361 |  |   |  |  |  |  |  |  |  |  |  |  |   | Current assets, net of cash |  | $ | 5,118 |  |  | $ | (2,554 | ) |  | $ | 2,564 |  |   | Equipment and other long-term assets |  |  | 2,212 |  |  |  | - |  |  |  | 2,212 |  |   | Intangible assets: |  |  |  |  |  |  |  |  |  |  |  |  |   | Developed technology |  |  | 180,000 |  |  |  | (75,000 | ) |  |  | 105,000 |  |   | Trade Name |  |  | - |  |  |  | 58,000 |  |  |  | 58,000 |  |   | Customer Relationships |  |  | - |  |  |  | 2,300 |  |  |  | 2,300 |  |   | Goodwill |  |  | 96,592 |  |  |  | 13,474 |  |  |  | 110,066 |  |   | Total assets acquired |  |  | 283,922 |  |  |  | (3,780 | ) |  |  | 280,142 |  |   | Liabilities |  |  | 2,624 |  |  |  | 210 |   |  |  | 2,834 |  |   | Deferred income taxes, net |  |  | 27,673 |  |  |  | (3,990 | ) |  |  | 23,683 |  |   | Net assets acquired |  | $ | 253,625 |  |  | $ | - |  |  | $ | 253,625 |  |   |  |  |  |  |  |  |  |  |  |  |  |  |  |   | Cash paid, net of cash acquired |  | $ | 251,825 |  |  | $ | - |  |  | $ | 251,825 |  |   | Fair value of contingent consideration |  |  | 1,800 |  |  |  | - |  |  |  | 1,800 |  |   | Net assets acquired |  | $ | 253,625 |  |  | $ | - |  |  | $ | 253,625 |  |  |