| 
           Intangible Assets (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        6 Months Ended | |
|---|---|---|
| 
           Jun. 30, 2012 
         | 
        
           Dec. 31, 2011 
         | 
      |
| Summary of acquired intangible assets | ||
| Gross Carrying Amount | $ 18,386 | $ 18,386 | 
| Accumulated Amortization | 5,039 | 4,386 | 
| 
           Patents [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 12 years | |
| Gross Carrying Amount | 1,271 | 1,271 | 
| Accumulated Amortization | 735 | 685 | 
| 
           Trade Names [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Gross Carrying Amount | 1,853 | 1,853 | 
| Accumulated Amortization | 72 | 7 | 
| 
           Trade Names [Member] | Minimum [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 0 years | |
| 
           Trade Names [Member] | Maximum [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 10 years | |
| 
           Completed and Unpatented Technology [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Gross Carrying Amount | 5,277 | 5,277 | 
| Accumulated Amortization | 1,472 | 1,242 | 
| 
           Completed and Unpatented Technology [Member] | Minimum [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 10 years | |
| 
           Completed and Unpatented Technology [Member] | Maximum [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 15 years | |
| 
           Backlog and Customer Relationships [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Gross Carrying Amount | 9,985 | 9,985 | 
| Accumulated Amortization | $ 2,760 | $ 2,452 | 
| 
           Backlog and Customer Relationships [Member] | Minimum [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 3 years | |
| 
           Backlog and Customer Relationships [Member] | Maximum [Member] 
         | 
        ||
| Summary of acquired intangible assets | ||
| Weighted Average Life | 20 years |