Leases (Lease-Related Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Sep. 30, 2020
Assets:
Operating lease assets	$ 20,061	$ 18,918
Finance lease assets	1,094	1,201
Total lease assets	21,155	20,119
Current liabilities:
Operating lease liabilities	4,950	4,925
Finance lease liabilities	1,623	1,634
Noncurrent liabilities:
Operating lease liabilities	15,683	14,569
Finance lease liabilities	802	1,173
Total lease liabilities	$ 23,058	$ 22,301