Maximum amount of loss due to credit risk that, based on the gross fair value of the financial instrument, the entity would incur if parties to the financial instruments that make up the concentration failed completely to perform according to the terms of the contracts and the collateral or other security, if any, for the amount due proved to be of no value to the entity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121572278&loc=d3e13537-108611

Name:	us-gaap_ConcentrationRiskCreditRiskFinancialInstrumentMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Guarantees, Commitments, and Contingencies (Narrative) (Details) - USD ($)		3 Months Ended	12 Months Ended	15 Months Ended
	Mar. 31, 2021	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
PPP Loans [Member] \| Small Business Administration [Member]
Commitments, Contingencies and Guarantees [Line Items]
Nonrefundable loan processing fees received	$ 15,882,000	$ 15,882,000	$ 20,883,000	$ 36,765,000
Financial Standby Letters of Credit [Member]
Commitments, Contingencies and Guarantees [Line Items]
Commitments to extend credit		$ 43,997,000	$ 39,468,000