XML 49 R31.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Regulated Operations (Policies) | 12 Months Ended
--- | ---
Dec. 31, 2023
Regulated Operations [Abstract] |
Insider Trading Policies and Procedures | Insider Trading Policies and Procedures. Our board of directors has adopted insider trading policies and procedures governing the purchase, sale, and/or other dispositions of our securities by directors, officers and employees, or by Cullen/Frost itself. These policies have been reasonably designed to promote compliance with insider trading laws, rules and regulations, and applicable New York Stock Exchange listing standards.

X
- Definition Insider Trading Policies and Procedures + References No definition available. + Details
Name: | cfr_InsiderTradingPoliciesAndProceduresPolicyTextBlock
Namespace Prefix: | cfr_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_RegulatedOperationsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration