Investment Securities - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Reclassification of securities held-to-maturity to securities available-for-sale		$ 18,800		$ 18,777	$ 0
Unrealized gain arising from the reclassification of securities held-to-maturity to securities available-for-sale	$ 0	$ 787	$ 0	$ 787	$ 0

Amount, before tax and adjustment, of unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

Name:	us-gaap_OtherComprehensiveIncomeReclassificationAdjustmentForHeldToMaturityTransferredToAvailableForSaleSecuritiesBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration