Short-term Borrowings - Narrative (Details) $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Short-term Debt [Line Items]
Federal home loan bank, advances, maturity period	90 days
Fixed Income Securities
Short-term Debt [Line Items]
Securities pledged to secure other short term borrowings	$ 2

Amount of restricted investment in debt security measured at fair value with change in fair value recognized in net income (trading).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 30
-Section 50
-Paragraph 1A
-Subparagraph (b)(1)(i)
-URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729

Name:	us-gaap_DebtSecuritiesTradingRestricted
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant