v3.25.1
Regulatory Capital Requirements (Details)
$ in Thousands
Mar. 31, 2025
USD ($)
Classification
Dec. 31, 2024
USD ($)
Trustco Bank [Member]    
Compliance With Regulatory Capital Requirements Under Banking Regulations Information [Abstract]    
Number of classifications for prompt corrective action regulations provide | Classification 5  
Tier One Risk Based Capital [Abstract]    
Tier 1 leverage capital $ 658,909 $ 652,668
Common equity Tier 1 capital 658,909 652,668
Tier 1 risk-based capital 658,909 652,668
Total risk-based capital $ 703,154 $ 696,767
Risk Based Ratios [Abstract]    
Tier 1 leverage ratio, ratio 0.10533 0.10618
Common equity Tier 1 capital, ratio 0.1866 0.18542
Tier 1 risk-based capital, ratio 0.1866 0.18542
Total risk-based capital, ratio 0.19913 0.19795
Leverage Ratios [Abstract]    
Tier 1 leverage ratio, well capitalized [1] 0.05 0.05
Tier 1 leverage ratio, minimum for capital adequacy [1],[2] 0.04 0.04
Common equity Tier 1 capital, well capitalized [1] 0.065 0.065
Common equity Tier 1 capital, minimum for capital adequacy plus capital conservation [1],[2] 0.07 0.07
Tier 1 risk-based capital, well capitalized [1] 0.08 0.08
Tier 1 risk-based capital, minimum for capital adequacy plus capital conservation [1],[2] 0.085 0.085
Total risk-based capital, well capitalized [1] 0.10 0.10
Total risk-based capital, minimum for capital adequacy plus capital conservation [1],[2] 0.105 0.105
Common equity Tier 1 capital conservation buffer 0.025 0.025
Tier 1 risk based capital ratio, capital conservation buffer 0.025 0.025
Total risk based capital ratio, capital conservation buffer 0.025 0.025
TrustCo Bank Corp NY [Member]    
Tier One Risk Based Capital [Abstract]    
Tier 1 leverage capital $ 687,387 $ 679,651
Common equity Tier 1 capital 687,387 679,651
Tier 1 risk-based capital 687,387 679,651
Total risk-based capital $ 731,643 $ 723,762
Risk Based Ratios [Abstract]    
Tier 1 leverage ratio, ratio 0.10984 0.11054
Common equity Tier 1 capital, ratio 0.19461 0.19303
Tier 1 risk-based capital, ratio 0.19461 0.19303
Total risk-based capital, ratio 0.20714 0.20556
Leverage Ratios [Abstract]    
Tier 1 leverage ratio, minimum for capital adequacy [1],[2] 0.04 0.04
Common equity Tier 1 capital, minimum for capital adequacy plus capital conservation [1],[2] 0.07 0.07
Tier 1 risk-based capital, minimum for capital adequacy plus capital conservation [1],[2] 0.085 0.085
Total risk-based capital, minimum for capital adequacy plus capital conservation [1],[2] 0.105 0.105
Common equity Tier 1 capital conservation buffer 0.025 0.025
Tier 1 risk based capital ratio, capital conservation buffer 0.025 0.025
Total risk based capital ratio, capital conservation buffer 0.025 0.025
[1] Federal regulatory minimum requirements to be considered to be Well Capitalized and Adequately Capitalized
[2] The March 31, 2025 and December 31, 2024 common equity tier 1, tier 1 risk-based, and total risk-based capital ratios include a capital conservation buffer of 2.50 percent