Variable Interest Entities - Amortization Expense and Tax Credits and Other Tax Benefits (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Investments in Qualified Affordable Housing Projects
Amortization expense	$ 1,936	$ 1,609	$ 5,766	$ 4,504
Tax credits and other tax benefits recognized	$ 2,608	$ 2,202	$ 7,771	$ 6,169

Amount of amortization expense of investment in qualified affordable housing projects.

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 (c)
-URI http://asc.fasb.org/extlink&oid=116633289&loc=SL49122993-202985

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration