Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 38,010	$ (101,659)	$ 84,453
Unrealized gains (losses) on AFS securities arising during the period, net of taxes of $(7,133), $(2,696), and $51,565	22,362	8,355	(159,770)
Amount reclassified from AOCI for sale of AFS Securities	(1,188)
Reclassification Adjustment from AOCI for Write-down of Securities, Net of Tax		145,622	0
Unrealized (losses) gains on cash flow hedges arising during the period, net of taxes of $701, $(1,923), and $(8,177)	(2,135)	5,957	25,339
Reclassification adjustment for cash flow hedge amounts included in net income, net of taxes of $1,967, $1,808, and $(1,647)	6,112	5,601	(5,103)
Comprehensive income (loss)	$ 50,937	$ 52,674	$ (44,875)