Other Comprehensive Income (Loss) (Details 1) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2016
Changes in the accumulated balances for each component of other comprehensive income
Beginning balance	$ 64,544
Ending balance	64,380	$ 64,544
Unrealized Gains (Losses) on Securities
Changes in the accumulated balances for each component of other comprehensive income
Beginning balance	614	(249)
Current year-to-date other comprehensive income (loss), net of tax	(1,267)	863
Ending balance	(653)	614
Defined Benefit Plans
Changes in the accumulated balances for each component of other comprehensive income
Beginning balance	0	35
Current year-to-date other comprehensive income (loss), net of tax	0	(35)
Ending balance	0	0
Other Accumulated Comprehensive Income (Loss)
Changes in the accumulated balances for each component of other comprehensive income
Beginning balance	614	(214)
Current year-to-date other comprehensive income (loss), net of tax	(1,267)	828
Ending balance	$ (653)	$ 614