Income Taxes (Unrecognized tax benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 4,210	$ 3,860	$ 3,510
Additions related to tax positions taken in prior years	155	350	350
Reductions due to resolution of uncertain tax position	(3,167)	0	0
Balance at the end of the year	$ 1,198	$ 4,210	$ 3,860