Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Interest income
Loans	$ 449,536	$ 498,935	$ 451,290
Investment securities	42,653	41,510	29,171
Federal funds sold and other	1,383	2,472	1,376
Total interest income	493,572	542,917	481,837
Interest expense
Deposits	58,603	106,718	60,112
FHLB advances and other borrowings	11,028	9,951	8,848
Subordinated debentures and subordinated notes payable	4,516	5,540	5,040
Total interest expense	74,147	122,209	74,000
Net interest income	419,425	420,708	407,837
Provision for loan and lease losses	118,392	40,947	17,986
Net interest income after provision for loan and lease losses	301,033	379,761	389,851
Noninterest income
Service charges and other fees	37,741	43,893	51,077
Wealth management fees	11,772	8,914	9,219
Mortgage banking income, net	8,959	4,848	5,842
Net gain (loss) on sale of securities	7,890	(178)	6
Net (decrease) increase in fair value of loans at fair value	(32,529)	61,412	(45,407)
Net realized and unrealized (loss) gain on derivatives	(38,439)	(63,444)	44,596
Other	4,623	5,287	8,276
Total noninterest income	17	60,732	73,609
Noninterest expense
Salaries and employee benefits	149,441	136,305	135,352
Data processing and communication	24,455	24,077	29,805
Occupancy and equipment	21,273	20,784	20,330
Professional fees	21,961	14,579	17,891
Advertising	3,396	4,493	4,507
Net loss on repossessed property and other related expenses	12,858	4,367	4,369
Goodwill and intangible assets impairment	742,352	0	0
Other	31,632	20,293	19,171
Total noninterest expense	1,007,368	224,898	231,425
(Loss) income before income taxes	(706,318)	215,595	232,035
(Benefit from) provision for income taxes	(25,510)	48,230	74,119
Net income	$ (680,808)	$ 167,365	$ 157,916
Basic earnings per common share
Weighted average shares outstanding, basic (in shares)	55,612,251	57,154,865	58,938,169
Basic earnings per share (in dollars per share)	$ (12.24)	$ 2.93	$ 2.68
Diluted earnings per common share
Weighted average shares outstanding, diluted (in shares)	55,612,251	57,257,061	59,131,650
Diluted earnings per share (in dollars per share)	$ (12.24)	$ 2.92	$ 2.67
Dividends per share
Dividends paid	$ 42,456	$ 62,904	$ 53,002
Dividends per share (in dollars per share)	$ 0.76	$ 1.10	$ 0.90