Low Income Housing Partnerships (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Investments in Affordable Housing Projects [Abstract]
Investment In affordable housing limited partnerships	$ 58,000	$ 41,800
Obligations related to investments in affordable housing limited partnerships	$ 27,200	14,600
Affordable housing tax credits commitment, year to be paid	2018
Affordable housing other tax benefits, amount	$ 1,100	963	$ 866
Affordable housing tax credits, amount	4,800	4,300	3,600
Impairment losses from the forfeiture or ineligibility of tax credits or other circumstances, amount	$ 0	$ 0	$ 0