Loans - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at lower of cost or fair value	$ 0		$ 0		$ 0
Release of losses	(761,000)	$ 451,000	152,000	$ 3,889,000
Real estate owned, amount of loss at acquisition		400,000
Rural Utilities
Accounts, Notes, Loans and Financing Receivable [Line Items]
Release of losses	(181,000)	1,397,000	821,000	3,522,000
Increase (decrease) in loan volume		311,800,000
Farm & Ranch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Release of losses	$ (626,000)	$ (920,000)	$ (653,000)	(112,000)
Rural Utilities and Farm & Ranch
Accounts, Notes, Loans and Financing Receivable [Line Items]
Release of losses				$ 3,400,000