Summary of Significant Accounting Policies - Narrative (Details) - USD ($)		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, after Allowance for Credit Loss	[2]	$ 1,122,238,000	[1]	$ 1,037,429,000	[3]
Federal reserve bank minimum reserve required		$ 750,000		$ 0
Number of days delinquent at which accrual of interest on loan is discontinued		90 days
Federal home loan bank stock, par value (usd per share)		$ 100
Subsidiaries [Member]
Loans and Leases Receivable Disclosure [Line Items]
Financing Receivable, after Allowance for Credit Loss		$ 1,000,000

[1] (1) There were no loans 90 days past due and still accruing interest at December 31, 2018.

[2] {F|ahBzfndlYmZpbGluZ3MtaHJkcmoLEgZYTUxEb2MiXlhCUkxEb2NHZW5JbmZvOmM4OGZhYWIzOTNiODRlMjdiYjMyMzc3NDdmYzYwZmJifFRleHRTZWxlY3Rpb246NjNERUZGNEVGRTk2MTQ3MUQ1OUExRjAyRTk4MzU1RUMM}

[3] (1) There were no loans 90 days past due and still accruing interest at December 31, 201