| 
           Goodwill and intangible assets (Details) (USD $) 
        In Thousands, unless otherwise specified  | 
        9 Months Ended | 
|---|---|
| 
           Jun. 30, 2014 
         | 
      |
| Changes in goodwill | |
| Balance at the beginning of the period | $ 171,867 | 
| Changes to allocation of HML purchase price | 31 | 
| Foreign currency translation | 3,573 | 
| Balance at the end of the period | 175,471 | 
| 
           Health Services [Member] 
         | 
        |
| Changes in goodwill | |
| Balance at the beginning of the period | 125,096 | 
| Changes to allocation of HML purchase price | 31 | 
| Foreign currency translation | 3,213 | 
| Balance at the end of the period | 128,340 | 
| 
           Human Services [Member] 
         | 
        |
| Changes in goodwill | |
| Balance at the beginning of the period | 46,771 | 
| Foreign currency translation | 360 | 
| Balance at the end of the period | $ 47,131 | 
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- Definition 
          Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition 
          Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
          
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- Definition 
          Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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