Business combinations (Details) $ in Thousands |
3 Months Ended | |||
|---|---|---|---|---|
|
Dec. 15, 2015
USD ($)
company
|
Dec. 31, 2015
USD ($)
|
Dec. 31, 2014
USD ($)
|
Sep. 30, 2015
USD ($)
|
|
| Business Acquisition [Line Items] | ||||
| Contingent consideration transferred | $ 2,606 | $ 0 | ||
| Goodwill | $ 387,118 | $ 376,302 | ||
| Assessments Australia | ||||
| Business Acquisition [Line Items] | ||||
| Percentage of business acquired | 100.00% | |||
| Number of businesses acquired | company | 3 | |||
| Contingent consideration transferred | $ 2,700 | |||
| Cash payments to acquire businesses | 2,600 | |||
| Contingent consideration | 100 | |||
| Contingent consideration arrangements, range of outcomes, value, high | 600 | |||
| Goodwill | 2,000 | |||
| Recognized identifiable assets acquired and liabilities assumed, intangible assets | $ 900 | |||
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition For contingent consideration arrangements recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the consideration which may be paid. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of liability recognized arising from contingent consideration in a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Amount of intangible assets, excluding goodwill, acquired at the acquisition date. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- 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
|
| X | ||||||||||
- Definition The number of businesses acquired by the entity during the period. No definition available.
|
| X | ||||||||||
- Definition The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|