XML 31 R77.htm IDEA: XBRL DOCUMENT v3.3.0.814
Capital and Regulatory Matters - Actual and Required Capital Ratios (Detail) - USD ($)
$ in Thousands
Sep. 30, 2015
Dec. 31, 2014
Cullen/Frost [Member]    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Common Equity Tier 1 to Risk-Weighted Assets, Actual, Capital Amount $ 1,979,694  
Common Equity Tier 1 to Risk-Weighted Assets, Actual , Ratio 11.57%  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 769,754  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Ratio 4.50%  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,197,002  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased In, Ratio 7.00%  
Common Equity Tier 1 to Risk-Weighted Assets, Required To Be Considered Well Capitalized, Capital Amount $ 1,111,867  
Common Equity Tier 1 to Risk-Weighted Assets, Required To Be Considered Well Capitalized, Ratio 6.50%  
Tier 1 Capital to Risk-Weighted Assets, Actual, Capital Amount $ 2,157,430 $ 2,185,558
Tier 1 Capital to Risk-Weighted Assets, Actual, Ratio 12.61% 13.67%
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 1,026,339  
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Ratio 6.00%  
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,453,503  
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Ratio 8.50%  
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount $ 1,368,452 $ 959,098
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio 8.00% 6.00%
Total Capital to Risk-Weighted Assets, Actual, Capital Amount $ 2,387,553 $ 2,325,100
Total Capital to Risk-Weighted Assets, Actual, Ratio 13.96% 14.55%
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 1,368,452  
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase - In Schedule, Ratio 8.00%  
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,795,503  
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Ratio 10.50%  
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount $ 1,710,565 $ 1,598,496
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio 10.00% 10.00%
Leverage Ratio, Actual, Capital Amount $ 2,157,430 $ 2,185,558
Leverage Ratio, Actual, Ratio 7.91% 8.16%
Leverage Ratio, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 1,091,452  
Leverage Ratio, Minimum Capital Required - Basel III Phase-In Schedule, Ratio 4.00%  
Leverage Ratio, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,091,227  
Leverage Ratio, Minimum Capital Required - Basel III Fully Phased-In, Ratio 4.00%  
Leverage Ratio, Required to be Considered Well Capitalized, Capital Amount $ 1,364,315 $ 1,340,043
Leverage Ratio, Required to be Considered Well Capitalized, Ratio 5.00% 5.00%
Tier 1 Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Capital Amount   $ 639,398
Tier 1 Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Ratio   4.00%
Total Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Capital Amount   $ 1,278,797
Total Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Ratio   8.00%
Leverage Ratio, Minimum Capital Required for Capital Adequacy Purposes, Capital Amount   $ 1,072,035
Leverage Ratio, Minimum Capital Required for Capital Adequacy Purposes, Ratio   4.00%
Frost Bank [Member]    
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Common Equity Tier 1 to Risk-Weighted Assets, Actual, Capital Amount $ 2,111,113  
Common Equity Tier 1 to Risk-Weighted Assets, Actual , Ratio 12.38%  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 767,137  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Ratio 4.50%  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,192,930  
Common Equity Tier 1 to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased In, Ratio 7.00%  
Common Equity Tier 1 to Risk-Weighted Assets, Required To Be Considered Well Capitalized, Capital Amount $ 1,108,086  
Common Equity Tier 1 to Risk-Weighted Assets, Required To Be Considered Well Capitalized, Ratio 6.50%  
Tier 1 Capital to Risk-Weighted Assets, Actual, Capital Amount $ 2,111,113 $ 1,978,697
Tier 1 Capital to Risk-Weighted Assets, Actual, Ratio 12.38% 12.41%
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 1,022,849  
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Ratio 6.00%  
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,448,558  
Tier 1 Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Ratio 8.50%  
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount $ 1,363,798 $ 956,894
Tier 1 Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio 8.00% 6.00%
Total Capital to Risk-Weighted Assets, Actual, Capital Amount $ 2,221,486 $ 2,070,293
Total Capital to Risk-Weighted Assets, Actual, Ratio 13.03% 12.98%
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 1,363,798  
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Phase - In Schedule, Ratio 8.00%  
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,789,396  
Total Capital to Risk-Weighted Assets, Minimum Capital Required - Basel III Fully Phased-In, Ratio 10.50%  
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Capital Amount $ 1,704,748 $ 1,594,823
Total Capital to Risk-Weighted Assets, Required to be Considered Well Capitalized, Ratio 10.00% 10.00%
Leverage Ratio, Actual, Capital Amount $ 2,111,113 $ 1,978,697
Leverage Ratio, Actual, Ratio 7.75% 7.40%
Leverage Ratio, Minimum Capital Required - Basel III Phase-In Schedule, Capital Amount $ 1,090,250  
Leverage Ratio, Minimum Capital Required - Basel III Phase-In Schedule, Ratio 4.00%  
Leverage Ratio, Minimum Capital Required - Basel III Fully Phased-In, Capital Amount $ 1,090,025  
Leverage Ratio, Minimum Capital Required - Basel III Fully Phased-In, Ratio 4.00%  
Leverage Ratio, Required to be Considered Well Capitalized, Capital Amount $ 1,362,812 $ 1,337,636
Leverage Ratio, Required to be Considered Well Capitalized, Ratio 5.00% 5.00%
Tier 1 Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Capital Amount   $ 637,929
Tier 1 Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Ratio   4.00%
Total Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Capital Amount   $ 1,275,858
Total Capital to Risk-Weighted Assets, Minimum Required for Capital Adequacy Purposes, Ratio   8.00%
Leverage Ratio, Minimum Capital Required for Capital Adequacy Purposes, Capital Amount   $ 1,070,109
Leverage Ratio, Minimum Capital Required for Capital Adequacy Purposes, Ratio   4.00%