Derivative Financial Instruments - Amounts Recorded in Balance Sheets Related to Cumulative Basis Adjustments (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Derivative Financial Instruments
Hedged Asset Carrying Amount	$ 23,290	$ 24,355
Hedged Asset, Fair Value Hedge, Cumulative Increase (Decrease)	$ 975	$ 1,487

Amount of cumulative increase (decrease) in fair value of hedged asset in fair value hedge, attributable to hedged risk.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4EE
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL109999712-113959

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