|**Acquisitions Acquisitions (Tables)**                                                                 | 6 Months Ended                                                                                                                                                                                                                                                                                                       
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|**Business Combinations [Abstract]**                                                                   |                                                                                                                                                                                                                                                                                                                      
|Schedule of Business Acquisitions, by Acquisition [Table Text Block]                                   | The following is a summary of the estimated fair values of the assets acquired and liabilities assumed from the acquisition:(In thousands)Current assets$327Property and equipment88Goodwill3,444Developed technology605Total assets acquired4,464Total liabilities assumed (all current)914Net assets acquired$3,550
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|(In thousands)                                                                                         |                                                                                                                                                                                                                                                                                                                      
|Current assets                                                                                         | $                                                                                                                                                                                                                                                                                                                    
|Property and equipment                                                                                 | 88                                                                                                                                                                                                                                                                                                                   
|Goodwill                                                                                               | 3,444                                                                                                                                                                                                                                                                                                                
|Developed technology                                                                                   | 605                                                                                                                                                                                                                                                                                                                  
|Total assets acquired                                                                                  | 4,464                                                                                                                                                                                                                                                                                                                
|Total liabilities assumed (all current)                                                                | 914                                                                                                                                                                                                                                                                                                                  
|Net assets acquired                                                                                    | $                                                                                                                                                                                                                                                                                                                    
|Schedule of Finite-Lived Intangible Assets Acquired as Part of Business Combination [Table Text Block] | The following is a summary of the intangible asset acquired and the weighted-average useful life over which it will be amortized.Weighted-averagePurchased assetsuseful lifeDeveloped technology$6055 years                                                                                                          
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|                                                                                                       | Purchased assets                                                                                                                                                                                                                                                                                                     
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|Developed technology                                                                                   | $                                                                                                                                                                                                                                                                                                                    

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