Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent [Abstract]
Unrealized holding gain (loss) on investment securities available-for-sale, taxes	$ (8)	$ (12)	$ 0
Reclassification adjustment for gain on sale of investment securities available-for-sale, taxes	0	0	0
Adjustments related to other factors for which OTTI was previously recognized, taxes	(2)	12	7
Amount reclassified to credit loss for previously recorded market loss, taxes	1	2	49
Accretion of OTTI on investment securities held-to-maturity, taxes	$ 10	$ 26	$ 18

Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for translation gain (loss) realized upon the sale or liquidation of an investment in a foreign entity and foreign currency hedges that are designated and qualified as hedging instruments for hedges of the foreign currency exposure of a net investment in a foreign operation.

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Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income for unrealized gain (loss) realized upon the sale of available-for-sale securities.

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Amount of tax (expense) benefit of other than temporary impairment (OTTI) on investment in available-for-sale debt security, recognized in other comprehensive loss, attributable to noncontrolling interest.

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