Consolidated Statements Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 15,462	$ 20,286
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred loan origination fees and costs	831	408
Net amortization of premiums and discounts on securities	608	283
Amortization on mortgage servicing rights	43	57
Amortization of debt issuance costs	27	27
Depreciation and amortization of office properties and equipment	1,764	1,684
Provision for loan losses	5,400	375
Gain on securities transactions, net	(55)	(411)
Gain on real estate owned, net	0	(197)
Deferred tax (benefit) expense	(2,679)	7,994
Increase in accrued interest receivable	(1,927)	(863)
Increase in cash surrender value of bank-owned life insurance	2,153	2,132
Increase in other assets	(12,611)	(12,935)
Increase (decrease) in accrued expenses and other liabilities	7,947	(438)
Net cash provided by operating activities	12,657	14,138
Cash flows from investing activities:
Proceeds from sales of securities available-for-sale	9,752	57,350
Proceeds from principal pay downs / maturities on securities available-for-sale	18,414	33,494
Proceeds from principal pay downs / maturities on securities held-to-maturity	3,795	0
Purchases of securities available-for-sale	(338,390)	(14,005)
Purchases of securities held-to-maturity	(125,146)	0
Purchases of loan receivables	(60,810)	(16,772)
Loan originations, net of principal payments	(118,283)	(257,039)
Proceeds from bank-owned life insurance	0	977
Proceeds from sales of Federal Home Loan Bank stock	34,241	21,240
Purchases of Federal Home Loan Bank stock	(27,778)	(24,111)
Additions to office properties and equipment	(4,635)	(2,649)
Proceeds from sales of real estate owned	0	1,409
Net cash used in investing activities	(608,840)	(200,106)
Cash flows from financing activities:
Net increase in deposits	1,271,825	135,544
Proceeds from long-term borrowings	26,360	342,700
Payments for maturities, calls, and payoffs on borrowings	(1,551,600)	(298,900)
Increase in short-term borrowings	1,381,600	10,000
Increase (decrease) in advance payments by borrowers for taxes and insurance	1,404	(3,108)
Net cash provided by financing activities	1,129,589	186,236
Net increase in cash and cash equivalents	533,406	268
Cash and cash equivalents at beginning of year	100,975	45,695
Cash and cash equivalents at end of year	634,381	45,963
Cash paid during the period for:
Interest	26,141	21,530
Income tax payments, net	7,278	9,791
Noncash investing and financing activities:
Transfer of loans receivable to real estate owned	$ 566	$ 145