Quarterly report pursuant to Section 13 or 15(d)

Business combinations (Schedule of the Valuation of the Intangible Assets Acquired) (Details)

v3.4.0.3
Business combinations (Schedule of the Valuation of the Intangible Assets Acquired) (Details)
$ in Thousands
 6 Months Ended
Mar. 31, 2016
USD ($)
Assessments Australia  
Business Acquisition [Line Items]  
Finite-lived intangible assets acquired $ 365
Ascend Management Innovations LLC  
Business Acquisition [Line Items]  
Finite-lived intangible assets acquired $ 22,300
Customer relationships | Assessments Australia  
Business Acquisition [Line Items]  
Finite-lived intangible asset, useful life 6 years
Finite-lived intangible assets acquired $ 365
Customer relationships | Ascend Management Innovations LLC  
Business Acquisition [Line Items]  
Finite-lived intangible asset, useful life 19 years
Finite-lived intangible assets acquired $ 20,400
Trade Names | Ascend Management Innovations LLC  
Business Acquisition [Line Items]  
Finite-lived intangible asset, useful life 1 year
Finite-lived intangible assets acquired $ 1,700
Technology-Based Intangible Assets | Ascend Management Innovations LLC  
Business Acquisition [Line Items]  
Finite-lived intangible asset, useful life 8 years
Finite-lived intangible assets acquired $ 200