Borrowed Funds [Line Items]

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- Definition

Debt Instrument Maturities Period

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No definition available.

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Maximum number of quarterly periods by which the corporation has the right to defer interest payments on junior subordinated deferrable interest debentures

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No definition available.

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- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

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Amount of short term borrowing where a bank borrows, at the federal funds rate, from another bank.

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of long-term debt (with maturities initially due after one year or beyond the operating cycle if longer) identified as Junior Subordinated Notes, which have a lower priority than senior instruments.

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The cash outflow to reacquire preferred stocks issued by a business trust or other special purpose entity, mainly established by a bank holding entity, to third party investors. The trust's assets are deeply subordinated debentures of the bank holding entity. Most trust preferred securities are subject to a mandatory redemption upon the repayment of the debentures.

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The cash inflow from issuance of preferred stocks by a business trust or other special purpose entity, mainly established by a bank holding entity, to third party investors. The trust's assets are deeply subordinated debentures of the bank holding entity. Most trust preferred securities are subject to a mandatory redemption upon the repayment of the debentures.

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Amount, after the effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

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- Definition

Stated interest rate of the subordinated debt.

+ References

No definition available.

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- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of subordinated debt (with initial maturities beyond one year or beyond the operating cycle if longer). Subordinated debt places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets.

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The remaining balance of debt issuance expenses that were capitalized and are being amortized against income over the lives of the respective bond issues. This does not include the amounts capitalized as part of the cost of the utility plant or asset.

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No definition available.

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Borrowed Funds (Narrative) (Detail) $ in Thousands		3 Months Ended	12 Months Ended
Borrowed Funds (Narrative) (Detail) $ in Thousands	Mar. 17, 2017 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2023 USD ($) quarter	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2004 USD ($)
Borrowed Funds [Line Items]
Federal funds purchased		$ 51,650	$ 14,200	$ 51,650
Repurchase agreements		4,660,641	4,127,188	4,660,641
Subordinated notes		99,335	99,491	99,335
Junior subordinated deferrable interest debentures		123,069	123,127	123,069
Principal payments on long-term borrowings			$ 0	0	$ 13,403
Maximum number of quarterly periods by which the corporation has the right to defer interest payments on junior subordinated deferrable interest debentures \| quarter			20
Cullen Frost Capital Trust II [Member]
Borrowed Funds [Line Items]
Maturity date						Mar. 01, 2034
Proceeds from Issuance of Trust Preferred Securities						$ 120,000
Proceeds from issuance of Common Equity Securities						$ 3,700
Cullen Frost Capital Trust II [Member] \| SOFR
Borrowed Funds [Line Items]
Floating rate 3 month Libor plus margin						1.81%
Cullen Frost Capital Trust II [Member] \| LIBOR [Member]
Borrowed Funds [Line Items]
Floating rate 3 month Libor plus margin						1.55%
Federal Funds Purchased [Member] \| Minimum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			1 day
Federal Funds Purchased [Member] \| Maximum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			90 days
Securities Loaned or Sold under Agreements to Repurchase [Member] \| Minimum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			30 days
Securities Loaned or Sold under Agreements to Repurchase [Member] \| Maximum [Member]
Borrowed Funds [Line Items]
Short term debt maturity period			90 days
Subordinated Debt [Member]
Borrowed Funds [Line Items]
Subordinated notes	$ 100,000
Subordinated notes interest rate	4.50%
Maturity date	Mar. 17, 2027
Unamortized debt issuance cost related to note		665	$ 509	665
Junior Subordinated Deferrable Interest Debenture [Member] \| Cullen Frost Capital Trust II [Member]
Borrowed Funds [Line Items]
Unamortized debt issuance cost related to note		643	585	643
Junior subordinated deferrable interest debentures		123,700	$ 123,700	$ 123,700		$ 123,700
Junior Subordinated Deferrable Interest Debenture [Member] \| Cullen Frost Capital Trust II [Member] \| SOFR
Borrowed Funds [Line Items]
Floating rate 3 month Libor plus margin			7.22%
Junior Subordinated Deferrable Interest Debenture [Member] \| Cullen Frost Capital Trust II [Member] \| LIBOR [Member]
Borrowed Funds [Line Items]
Floating rate 3 month Libor plus margin				6.31%
Junior Subordinated Deferrable Interest Debenture [Member] \| WNB Capital Trust I [Member]
Borrowed Funds [Line Items]
Principal payments on long-term borrowings		$ 13,400