Derivative Instruments [Line Items]

No definition available.

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- Definition

Nominal or face amount used to calculate payments on the derivative asset.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Nominal or face amount used to calculate payments on the derivative liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (b)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959

+ Details

Name:	us-gaap_DerivativeLiabilityNotionalAmount
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Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant

- Definition

Fair value as of the balance sheet date of all foreign currency derivative assets not designated as hedging instruments.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(2)
-URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5624163-113959

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value as of the balance sheet date of all foreign currency derivative liabilities not designated as hedging instruments.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=cfr_GBPForeignExchangeForwardMember
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- Details

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- Details

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Derivative Financial Instruments - Schedule of Notional Amounts and Fair Values of Open Foreign Currency Forward Contracts (Details) € in Thousands, $ in Thousands	Mar. 31, 2023 USD ($)	Mar. 31, 2023 EUR (€)	Dec. 31, 2022 USD ($)	Dec. 31, 2022 EUR (€)
Financial Institution Counterparties [Member] \| GBP Foreign Exchange Forward
Derivative Instruments [Line Items]
Forward Contracts – Assets Estimated Fair Value \| $	$ 0		$ 1
Forward Contracts - Liability Estimated Fair Value \| $	(176)		(10)
Financial Institution Counterparties [Member] \| Other Assets [Member] \| Non Designated as Hedging Instrument [Member]
Derivative Instruments [Line Items]
Forward Contracts – Assets Notional Amount \| €		€ 0		€ 875
Financial Institution Counterparties [Member] \| Other Liabilities [Member] \| Non Designated as Hedging Instrument [Member]
Derivative Instruments [Line Items]
Forward Contracts – Liability Notional Amount \| €		7,000		875
Customer Counterparties [Member] \| GBP Foreign Exchange Forward
Derivative Instruments [Line Items]
Forward Contracts – Assets Estimated Fair Value \| $	186		10
Forward Contracts - Liability Estimated Fair Value \| $	$ 0		$ (1)
Customer Counterparties [Member] \| Other Assets [Member] \| Non Designated as Hedging Instrument [Member]
Derivative Instruments [Line Items]
Forward Contracts – Assets Notional Amount \| €		7,000		875
Customer Counterparties [Member] \| Other Liabilities [Member] \| Non Designated as Hedging Instrument [Member]
Derivative Instruments [Line Items]
Forward Contracts – Liability Notional Amount \| €		€ 0		€ 875