Summary of Significant Accounting Policies (Adoption of ASC 842) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Oct. 01, 2019	Sep. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 14,334		$ 0
Operating lease liabilities	$ 16,193		$ 0
ASU 2016-02 | Other non-current assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 14,100
ASU 2016-02 | Other non-current liabilities
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease liabilities		$ 17,900