Amount of allowance for credit loss on 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/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 50
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
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-Section 50
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
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-URI http://asc.fasb.org/extlink&oid=124258926&loc=SL82898722-210454

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Amount of expense for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), for which no credit loss was previously recorded.

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- Definition

Amount of expense (reversal of expense) for allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), not intended to be sold and not more likely than not will be required to sell before recovery of amortized cost basis, with previously recorded allowance.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Investment Securities - Allowance for Credit Loss Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Jan. 01, 2020
Debt Securities, Available-for-sale [Line Items]
Securities, available-for-sale, allowance for credit loss, beginning balance		$ (869)
Adjustment to initially apply ASU No. 2016-13 for CECL		(815)
Securities, available-for-sale, allowance for credit loss, ending balance		(815)
Corporate Bonds [Member]
Debt Securities, Available-for-sale [Line Items]
Securities, available-for-sale, allowance for credit loss, beginning balance		(869)	$ 0
Adjustment to initially apply ASU No. 2016-13 for CECL	$ (692)	(815)	(692)
Additions for securities for which no previous expected credit losses were recognized	(1)	(22)
Change in securities for which a previous expected credit loss was recognized		76	(391)
Securities, available-for-sale, allowance for credit loss, ending balance	$ (692)	$ (815)	$ (692)
Corporate Bonds [Member] \| Cumulative Effect, Period Of Adoption, Adjustment
Debt Securities, Available-for-sale [Line Items]
Adjustment to initially apply ASU No. 2016-13 for CECL				$ (300)