CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income before noncontrolling interest	$ 159,354	$ 145,745	$ 109,344
Other comprehensive income (loss):
Change in net unrealized gain (loss) on debt securities	(293,952)	(13,896)	15,164
Net loss (gain) realized on investment securities	1,287	(6)	(51)
Total available for sale adjustment	(292,665)	(13,902)	15,113
Unrealized gain (loss) on currency translation	(1,736)	476	(101)
Deferred income tax effect	(73,722)	(3,483)	3,809
Total other comprehensive income (loss)	(220,679)	(9,943)	11,203
Total comprehensive income (loss)	(61,325)	135,802	120,547
Total comprehensive income attributable to noncontrolling interest	2,968	4,037	4,624
Comprehensive income (loss) attributable to parent	$ (64,293)	$ 131,765	$ 115,923