Affordable Housing Projects Tax Credit Partnerships - Additional Information (Details) - USD ($)	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Equity Method Investments And Joint Ventures [Abstract]
Net affordable housing tax credit investments and related unfunded commitments	$ 117,900,000		$ 76,300,000
Write down from impairment of LIHTC Investments	$ 0	$ 0

Amount of write-down from impairment of an investment in a qualified affordable housing project.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 740
-Section 50
-Paragraph 2
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=116633289&loc=SL49122993-202985

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