Loans Held for Investment - Schedule of Restructured Loans by Type, Net of Individually Evaluated Allowances (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2020 USD ($) loan	Jun. 30, 2020 USD ($) loan
Financing Receivable, Impaired [Line Items]
Number of modified loans | loan	23	8
Restructured Loans, Allowance for Loan Losses	$ (587)	$ (112)
Restructured Loans, Unpaid Principal Balance	9,160	3,120
Restructured Loans, Related Charge-offs	(365)	(365)
Restructured Loans, Recorded Investment	8,795	2,755
Restructured loans, net investment	8,208	2,643
Mortgage loans, Single-family
Financing Receivable, Impaired [Line Items]
Restructured Loans, With Related Allowance, Unpaid Principal Balance	7,939	1,650
Restructured Loans, With Related Allowance, Related Charge-offs		0
Restructured Loans, With a Related Allowance, Recorded Investment	7,939	1,650
Restructured Loans, Allowance for Loan Losses	(587)	(108)
Restructured loans, with a related allowance, net investment	7,352	1,542
Restructured Loans, Without a Related Allowance, Unpaid Principal Balance	1,221	1,435
Restructured Loans, Without a Related Allowance, Related Charge-offs	(365)	(365)
Restructured Loans, Without a Related Allowance, Recorded Investment	856	1,070
Restructured Loans, Without a Related Allowance, Net Investment	856	1,070
Restructured Loans, Unpaid Principal Balance	9,160	3,085
Restructured Loans, Related Charge-offs	(365)	(365)
Restructured Loans, Recorded Investment	8,795	2,720
Restructured loans, net investment	$ 8,208	2,612
Commercial business loans
Financing Receivable, Impaired [Line Items]
Restructured Loans, With Related Allowance, Unpaid Principal Balance		35
Restructured Loans, With Related Allowance, Related Charge-offs		0
Restructured Loans, With a Related Allowance, Recorded Investment		35
Restructured Loans, Allowance for Loan Losses		(4)
Restructured Loans, Unpaid Principal Balance		35
Restructured Loans, Related Charge-offs		0
Restructured Loans, Recorded Investment		35
Restructured loans, net investment		$ 31