Loans Loans - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Jul. 01, 2020	Sep. 30, 2019	Jun. 30, 2019
Accounts, Notes, Loans and Financing Receivable
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201613Member
Deferred cost	$ 1,941
Unamortized discount total related to loans acquired	5,126
Accrued interest receivable	9,859
Allowance for credit losses	43,132	$ 28,072	$ 28,072	$ 21,314	$ 21,429
Nonaccrual loans	14,420	15,923
Reserve for credit losses for off-balance sheet credit exposures included in other liabilities	2,288		0
PCI
Accounts, Notes, Loans and Financing Receivable
Allowance for credit losses		182		194	201
Nonaccrual loans	965
Retail Consumer Loans
Accounts, Notes, Loans and Financing Receivable
Allowance for credit losses	17,933	6,956	6,956	5,728	6,419
Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Allowance for credit losses	25,199	$ 21,116	$ 21,116	$ 15,392	$ 14,809
Coronavirus Aid, Relief, And Economic Securities Act, Short-Term Modifications | Retail Consumer Loans
Accounts, Notes, Loans and Financing Receivable
Total modifications	1,106
Coronavirus Aid, Relief, And Economic Securities Act, Short-Term Modifications | Commercial Loans
Accounts, Notes, Loans and Financing Receivable
Total modifications	$ 90,138