Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation - Narrative (Details)

v3.8.0.1
Basis of Presentation - Narrative (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2018
Mar. 31, 2017
Sep. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Reduction to income tax expense         $ 1,234
Diluted (in dollars per share) $ 0.57 $ 0.46 $ 1.68 $ 0.77  
Accounting Standards Update 2016-09          
New Accounting Pronouncements or Change in Accounting Principle [Line Items]          
Diluted (in dollars per share)         $ 0.04