XML 65 R55.htm IDEA: XBRL DOCUMENT v3.23.1

Derivative Instruments and Hedging Activities (Effect of Fair Value Hedges on Consolidated Statements of Income) (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	$ 1,331	$ 3,010
Interest rate contracts
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	18	673
Mortgage derivatives | Mortgage derivatives - interest rate lock commitments
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	1,109	(1,318)
Mortgage derivatives | Mortgage derivatives - forward commitments to sell fixed-rate mortgage loans
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	(328)	3,565
Risk participation agreements
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	3	25
Foreign exchange contracts
Derivative [Line Items]
Gain (Loss) Recognized in Consolidated Statements of Income	$ 529	$ 65

X

- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
-Subparagraph (b)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480434/815-10-50-4A

+ Details

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

X

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480237/815-40-50-5

+ Details

Name:	us-gaap_DerivativeLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_HedgingDesignationAxis=us-gaap_NondesignatedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=syn_MortgageDerivativeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_InterestRateLockCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_FinancialInstrumentAxis=syn_ForwardcommitmentstosellfixedratemortgageloansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=syn_RiskParticipationAgreementsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: