Income Taxes (Unrecognized tax benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of the year	$ 3,860	$ 3,510	$ 3,180
Additions related to tax positions taken in prior years	350	350	330
Reductions due to lapse of statute of limitations	0	0	0
Balance at the end of the year	$ 4,210	$ 3,860	$ 3,510