Troubled Debt Restructurings (Narrative) (Details)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2020 USD ($) contract loan	Sep. 30, 2020 USD ($) contract loan	Dec. 31, 2019 USD ($) contract
Financing Receivable Modifications [Line Items]
Number of troubled debt restructured loans		16	18
Loan is considered payment default		30 days
Financing Receivable, Modifications, Nonaccrual, Number of Contracts	2	2	4
Financing Receivable, Modifications, Nonaccrual, Recorded Investment | $	$ 126,000	$ 126,000	$ 401,000
Total troubled debt restructured loans | $	$ 2,800,000	$ 2,800,000	$ 3,000,000
Number of deferral loans of interest and principal payments | loan	251	251
Deferrals on outstanding loan balances | $	$ 97,900,000	$ 97,900,000
Number of loans making payment after deferral option passed | loan	231	231
Consumer Installment
Financing Receivable Modifications [Line Items]
Number of contracts modified by changing the amortization period	1	1
Residential Single Family
Financing Receivable Modifications [Line Items]
Number of contracts modified by changing the amortization period	1	1
Number of contracts modified by new policy exception	1	1
Number of contracts modified by reduced payment amount	1	1
Payment Deferral [Member] | CARES Act [Member]
Financing Receivable Modifications [Line Items]
Deferrals on outstanding loan balances | $	$ 134,000.0	$ 134,000.0