Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 19,474	$ 22,897	$ 46,261	$ 71,834
Unrealized gains (losses) on AFS securities arising during the period, net of taxes of $(1,775), $(1,317), $(4,962) and $(3,432)	5,533	4,102	15,459	10,690
Changes in unrealized gains (losses) on cash flow hedges, net of taxes of $367, $3,601, $5,826 and $8,847	(1,146)	(11,218)	(18,151)	(27,562)
Comprehensive (loss) income	$ 23,861	$ 15,781	$ 43,569	$ 54,962