Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Operating activities
Net (loss) income	$ (691,944)	$ 117,080
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	13,152	8,415
Amortization of FDIC indemnification asset	1,012	1,154
Net loss on sale of securities and other assets	6,649	2,727
Net gain on sale of loans	(5,840)	(3,971)
Provision for loan and lease losses	101,539	38,965
Goodwill and intangible assets impairment	742,352	0
Provision for (reversal of) loan servicing rights loss	6	(1)
Stock-based compensation	2,750	3,264
Originations of residential real estate loans held for sale	(231,420)	(171,233)
Proceeds from sales of residential real estate loans held for sale	231,771	174,420
Net deferred income taxes	(56,659)	21
Changes in:
Accrued interest receivable	744	1,598
Other assets	(71,570)	(24,363)
Accrued interest payable and other liabilities	20,128	158
Net cash provided by operating activities	62,670	148,234
Investing activities
Purchase of securities available for sale	(540,697)	(666,901)
Proceeds from sales of securities available for sale	0	145,627
Proceeds from maturities of securities available for sale	387,950	158,464
Net increase in loans	(633,971)	(519,597)
(Payment) recovery of covered losses from FDIC indemnification claims	(46)	26
Purchase of premises and equipment	(4,988)	(11,980)
Proceeds from sale of premises and equipment	0	605
Proceeds from sale of repossessed property	18,798	8,422
Purchase of FHLB stock	(113,437)	(72,948)
Proceeds from redemption of FHLB stock	112,992	59,869
Net cash paid in business acquisition	(4,711)	0
Net cash used in investing activities	(778,110)	(898,413)
Financing activities
Net increase in deposits	850,367	502,568
Net increase (decrease) in securities sold under agreements to repurchase and other short-term borrowings	1,370	(33,982)
Proceeds from FHLB advances and other long-term borrowings	680,000	795,000
Repayments on FHLB advances and other long-term borrowings	(665,000)	(465,000)
Common stock repurchased	(39,983)	(74,659)
Taxes paid related to net share settlement of equity awards	(1,297)	(1,236)
Dividends paid	(41,906)	(45,852)
Net cash provided by financing activities	783,551	676,839
Net increase (decrease) in cash and cash equivalents	68,111	(73,340)
Cash and cash equivalents, beginning of period	243,474	298,696
Cash and cash equivalents, end of period	311,585	225,356
Supplemental disclosure of cash flow information
Cash payments for interest	71,423	81,585
Cash payments for income taxes	21,089	37,708
Supplemental disclosure of noncash investing and financing activities
Loans transferred to repossessed properties	$ (7,762)	$ (23,625)